| 1. |
- Berthomier, M., et al.
(författare)
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Alfven : magnetosphere-ionosphere connection explorers
- 2012
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Ingår i: Experimental astronomy. - Dordrecht : Springer. - 0922-6435 .- 1572-9508. ; 33:2-3, s. 445-489
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Tidskriftsartikel (refereegranskat)abstract
- The aurorae are dynamic, luminous displays that grace the night skies of Earth's high latitude regions. The solar wind emanating from the Sun is their ultimate energy source, but the chain of plasma physical processes leading to auroral displays is complex. The special conditions at the interface between the solar wind-driven magnetosphere and the ionospheric environment at the top of Earth's atmosphere play a central role. In this Auroral Acceleration Region (AAR) persistent electric fields directed along the magnetic field accelerate magnetospheric electrons to the high energies needed to excite luminosity when they hit the atmosphere. The "ideal magnetohydrodynamics" description of space plasmas which is useful in much of the magnetosphere cannot be used to understand the AAR. The AAR has been studied by a small number of single spacecraft missions which revealed an environment rich in wave-particle interactions, plasma turbulence, and nonlinear acceleration processes, acting on a variety of spatio-temporal scales. The pioneering 4-spacecraft Cluster magnetospheric research mission is now fortuitously visiting the AAR, but its particle instruments are too slow to allow resolve many of the key plasma physics phenomena. The Alfv,n concept is designed specifically to take the next step in studying the aurora, by making the crucial high-time resolution, multi-scale measurements in the AAR, needed to address the key science questions of auroral plasma physics. The new knowledge that the mission will produce will find application in studies of the Sun, the processes that accelerate the solar wind and that produce aurora on other planets.
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| 2. |
- Yao, Shutao, et al.
(författare)
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Observations of kinetic-size magnetic holes in the magnetosheath
- 2017
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Ingår i: Journal of Geophysical Research - Space Physics. - : AMER GEOPHYSICAL UNION. - 2169-9380 .- 2169-9402. ; 122:2, s. 1990-2000
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Tidskriftsartikel (refereegranskat)abstract
- Magnetic holes (MHs), with a scale much greater than ρi (proton gyroradius), have been widely reported in various regions of space plasmas. On the other hand, kinetic-size magnetic holes (KSMHs), previously called small-size magnetic holes, with a scale of the order of magnitude of or less than ρi have only been reported in the Earth's magnetospheric plasma sheet. In this study, we report such KSMHs in the magnetosheath whereby we use measurements from the Magnetospheric Multiscale mission, which provides three-dimensional (3-D) particle distribution measurements with a resolution much higher than previous missions. The MHs have been observed in a scale of 10-20 ρe (electron gyroradii) and lasted 0.1-0.3 s. Distinctive electron dynamics features are observed, while no substantial deviations in ion data are seen. It is found that at the 90 degrees pitch angle, the flux of electrons with energy 34-66 eV decreased, while for electrons of energy 109-1024 eV increased inside the MHs. We also find the electron flow vortex perpendicular to the magnetic field, a feature self-consistent with the magnetic depression. Moreover, the calculated current density is mainly contributed by the electron diamagnetic drift, and the electron vortex flow is the diamagnetic drift flow. The electron magnetohydrodynamics soliton is considered as a possible generation mechanism for the KSMHs with the scale size of 10-20 ρe.
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| 3. |
- Yao, S. T., et al.
(författare)
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Propagation of small size magnetic holes in the magnetospheric plasma sheet
- 2016
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Ingår i: Journal of Geophysical Research - Space Physics. - : Wiley-Blackwell. - 2169-9380 .- 2169-9402. ; 121:6, s. 5510-5519
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Tidskriftsartikel (refereegranskat)abstract
- Magnetic holes (MHs), characteristic structures where the magnetic field magnitude decreases significantly, have been frequently observed in space plasmas. Particularly, small size magnetic holes (SSMHs) which the scale is less than or close to the proton gyroradius are recently detected in the magnetospheric plasma sheet. In this study of Cluster observations, by the timing method, the minimum directional difference (MDD) method, and the spatiotemporal difference (STD) method, we obtain the propagation velocity of SSMHs in the plasma flow frame. Furthermore, based on electron magnetohydrodynamics (EMHD) theory we calculate the velocity, width, and depth of the electron solitary wave and compare it to SSMH observations. The result shows a good accord between the theory and the observation.
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| 4. |
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| 5. |
- Meredith, S. J., et al.
(författare)
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Return to sport after anterior cruciate ligament injury: Panther Symposium ACL Injury Return to Sport Consensus Group
- 2020
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Ingår i: Knee Surgery Sports Traumatology Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 28, s. 2403-2414
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Tidskriftsartikel (refereegranskat)abstract
- Purpose A precise and consistent definition of return to sport (RTS) after anterior cruciate ligament (ACL) injury is lacking, and there is controversy surrounding the process of returning patients to sports and their previous activity level. The aim of the Panther Symposium ACL Injury RTS Consensus Group was to provide a clear definition of RTS and description of the RTS continuum, as well as to provide clinical guidance on RTS testing and decision-making. Methods An international, multidisciplinary group of ACL experts convened as part of a consensus meeting. Consensus statements were developed using a modified Delphi method. Literature review was performed to report the supporting evidence. Results Key points include that RTS is characterized by achievement of the pre-injury level of sport and involves a criteria-based progression from return to participation to return to sport, and ultimately return to performance. Purely time-based RTS decision-making should be abandoned. Progression occurs along a RTS continuum with decision-making by a multidisciplinary group that incorporates objective physical examination data and validated and peer-reviewed RTS tests, which should involve functional assessment as well as psychological readiness. Consideration should be given to biological healing, contextual factors and concomitant injuries. Conclusion The resultant consensus statements and scientific rationale aim to inform the reader of the complex process of RTS after ACL injury that occurs along a dynamic continuum. Research is needed to determine the ideal RTS test battery, the best implementation of psychological readiness testing and methods for the biologic assessment of healing and recovery.
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| 6. |
- Meredith, S. J., et al.
(författare)
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Return to sport after anterior cruciate ligament injury: Panther Symposium ACL Injury Return to Sport Consensus Group
- 2021
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Ingår i: Journal of Isakos Joint Disorders & Orthopaedic Sports Medicine. - : Elsevier BV. - 2059-7754. ; 6:3, s. 138-146
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Tidskriftsartikel (refereegranskat)abstract
- Objectives A precise and consistent definition of return to sport (RTS) after anterior cruciate ligament (ACL) injury is lacking, and there is controversy surrounding the process of returning patients to sports and their previous activity level. The aim of the Panther Symposium ACL Injury RTS Consensus Group was to provide a clear definition of RTS after ACL injury and description of the RTS continuum, as well as provide clinical guidance on RTS testing and decision-making. Methods An international, multidisciplinary group of ACL experts convened as part of a consensus meeting. Consensus statements were developed using a modified Delphi method. Literature review was performed to report the supporting evidence. Results Key points include that RTS is characterised by achievement of the preinjury level of sport and involves a criteria-based progression from return to participation to RTS, and ultimately return to performance. Purely time-based RTS decision-making should be abandoned. Progression occurs along an RTS continuum with decision-making by a multidisciplinary group that incorporates objective physical examination data and validated and peer-reviewed RTS tests, which should involve functional assessment as well as psychological readiness. Consideration should be given to biological healing, contextual factors and concomitant injuries. Conclusion The resultant consensus statements and scientific rationale aim to inform the reader of the complex process of RTS after ACL injury that occurs along a dynamic continuum. Research is needed to determine the ideal RTS test battery, the best implementation of psychological readiness testing and methods for the biological assessment of healing and recovery.
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| 7. |
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| 8. |
- Persson, L., et al.
(författare)
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TROPHIC INTERACTIONS IN TEMPERATE LAKE ECOSYSTEMS - A TEST OF FOOD-CHAIN THEORY
- 1992
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Ingår i: American Naturalist. ; 140:1, s. 59-84
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Tidskriftsartikel (refereegranskat)abstract
- In a comparative study covering 11 temperate lake ecosystems of low to intermediate productivity, we tested the predictions of the food chain model developed by L. Oksanen et al. The pelagic habitat of the most unproductive lakes lacked secondary carnivores (piscivores), whereas secondary carnivores inhabited the more productive lakes in agreement with the assumption that food chain length is limited by the productivity of the system. The observed relationships between planktivores (primary carnivores), zooplankton (herbivores), and phytoplankton (primary producers) were in agreement with the predictions of the Oksanen et al. model for three- and four-trophic-link systems. Piscivore relationships were significant only when the biomass of piscivorous perch only was used as the independent variable (piscivorous perch amounted to greater-than-or-equal-to 97% of total piscivore biomass in five out of six four-link systems). The results suggest that gross patterns of food web dynamics in temperate lakes may be collapsed into food chain dynamics. However, as the higher trophic levels of most lakes were dominated by the same two species, an alternative hypothesis is that the simplicity of the food webs studied allowed food chain dynamics to approximate food web dynamics. The food chain model tested gave accurate predictions of trophic-level relationships within the rather narrow productivity range studied. However, previous data suggest that, due to size-structured interactions, secondary carnivores (piscivores) play a minor role in highly productive systems, a circumstance that may explain the postulated increase in mortality rate of zooplankton with increasing productivity. The observed increase in number of trophic levels with productivity does not necessarily imply a causal relationship between productivity and food chain length, as lake productivity is also correlated with structural complexity (in the form of submerged vegetation and an oxygenated hypolimnion). Habitat heterogeneity may thus influence food chain length, and in general it is likely that food chain length will depend on more than one environmental variable.
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| 9. |
- Pitkänen, Timo, 1979-, et al.
(författare)
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IMF By Influence on Magnetospheric Convection in Earth's Magnetotail Plasma Sheet
- 2019
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Ingår i: Geophysical Research Letters. - : Blackwell Publishing Ltd. - 0094-8276 .- 1944-8007. ; 46:21, s. 11698-11708
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Tidskriftsartikel (refereegranskat)abstract
- We use Geotail, Cluster, and Time History of Events and Macroscale Interactions during Substorms data over 15 years (1995–2009) to statistically investigate convective ion flows (V⊥xy<200 km/s) in the magnetotail plasma sheet under the influence of a clearly nonzero dawn-dusk interplanetary magnetic field (IMF By). We find that IMF By causes an interhemispheric asymmetry in the flows, which depends on the direction of IMF By. On the average, one magnetic hemisphere is dominated by a dawn-dusk flow component, which is oppositely directed compared to that in the other hemisphere. This asymmetry is observed for both earthward and tailward flows. A comparison to tail By reveals that the region where the asymmetry in the average flows appears agrees with the appearance of the tail By direction collinear to IMF By. The results imply that IMF By has a major influence on the direction of the magnetic flux transport in the magnetotail.
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| 10. |
- Pitkänen, Timo, 1979-, et al.
(författare)
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Statistical Survey of Magnetic Forces Associated With Earthward Bursty Bulk Flows Measured by MMS 2017-2021
- 2023
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Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 128:5
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the magnetic forces (the magnetic pressure gradient force, the curvature force, and their sum the j x B-force) associated with earthward bursty bulk flows (BBFs) using Magnetospheric Multiscale (MMS) data from five tail seasons (2017-2021). For the first time, the magnetic forces are inferred downtail of XGSM = -20 R-E and in the GSM XY and YZ planes. The results suggest that BBFs tend to be accelerated earthward by the magnetic pressure gradient force tailward of similar to 19 R-E and decelerated closer to that distance in the 2017-2018 data. The force magnitudes increase with distance. This is in accordance with earlier Cluster results. In the 2019-2021 data, the pressure gradient force magnitudes are generally smaller and no clear distance for the acceleration reversal can be determined. The curvature forces for both 2017-2018 and 2019-2021 BBFs indicate earthward acceleration independent of distance, consistent with the Cluster measurements. The sum, the j x B-force, suggests for the 2017-2018 BBFs earthward acceleration tailward of XGSM similar to 15 R-E and deceleration within that distance, also consistent with Cluster. In contrast, the 2019-2021 BBFs show general earthward acceleration by j x B independent of distance. In the GSM XY plane, the average (j x B)(xy) vectors are earthward, and in the premidnight and postmidnight dawnward for the 2017-2018 BBFs. For 2019-2021, the average (j x B)(xy) vectors have components toward the tail center. In the GSM YZ plane, the average (j x B)(yz) vectors are toward the neutral sheet.
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| 11. |
- Xiao, Y.C., et al.
(författare)
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Statistical properties of the distribution and generation of kinetic-scale flux ropes in the terrestrial dayside magnetosheath
- 2023
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Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 50:23
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Tidskriftsartikel (refereegranskat)abstract
- The generation of kinetic-scale flux ropes (KSFRs) is closely related to magnetic reconnection. Both flux ropes and reconnection sites are detected in the magnetosheath and can impact the dynamics upstream of the magnetopause. In this study, using the Magnetospheric Multiscale satellite, 12,623 KSFRs with a scale <20 RCi are statistically studied in the Earth's dayside magnetosheath. It is found that they are mostly generated near the bow shock (BS), and propagate downstream in the magnetosheath. Their quantity significantly increases as the scale decreases, consistent with a flux rope coalescence model. Moreover, the solar wind parameters can control the occurrence rate of KSFRs. They are more easily generated at high Mach number, large proton density, and weak magnetic field strength of the solar wind, similar to the conditions that favor BS reconnection. Our study shows a close connection between KSFR generation and BS reconnection.
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| 12. |
- Yao, S. T., et al.
(författare)
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Propagating and Dynamic Properties of Magnetic Dips in the Dayside Magnetosheath : MMS Observations
- 2020
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Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 125:6
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Tidskriftsartikel (refereegranskat)abstract
- The magnetosheath is inherently complex and rich, exhibiting various kinds of structures and perturbations. It is important to understand how these structures propagate and evolve and how they relate to the perturbations. Here we investigate a kind of magnetosheath structure known as a magnetic dip (MD). As far as we are aware, there have been no previous studies concerning the evolution (contracting or expanding) of these types of structures, and their propagation properties cannot be unambiguously determined. In this study, using Magnetospheric MultiScale (MMS) high-temporal resolution data and multispacecraft analysis methods, we obtain the propagation and dynamic features of a set of MDs. Four different types of MDs are identified: "frozen-in," "expanding," "contracting," and "stable-propagating." Significantly, a stable-propagation event is observed with a sunward propagation component. This indicates that the source of the structure in this case is closely associated with the magnetopause, which provides strong support to the contention in earlier research. We further reveal the mechanism leading to the MD contraction or expansion. The motion of the MDs boundary is found closely related with the dynamic pressure. The scale of the contracting and expanding events are typically similar to 5-20 rho(i) (ion gyroradius), significantly smaller than that of frozen-in events (similar to 40 rho(i)). The observations could relate large-scale (more than several tens of rho(i)) and kinetic-scale (less than rho(i)) MDs, by revealing an evolution that spans these different scales, and help us better understand the variation and dynamics of magnetosheath structures and plasmas.
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| 13. |
- Andréasson, S, et al.
(författare)
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Medical laboratory technologists' perception of professional self. A study of Swedish MLTs employed in clinical chemistry
- 1992
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Ingår i: Scandinavian Journal of Caring Sciences. - 0283-9318 .- 1471-6712. ; 6:2, s. 67-74
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Tidskriftsartikel (refereegranskat)abstract
- The subjective perception of professional self was studied for a sample of Medical Laboratory Technologists (MLTs) employed in Clinical Chemistry in Sweden. The sample (N = 488) consisted of a randomized tenth of members of their trade union. A mailed questionnaire with 21 items concerning self-description compared with peers in a seven-point Likert type scale was completed by 332 (68%). There was no significant overall difference concerning the four principal types of workplace: Clinical Chemistry, Blood Serology, Primary Care and Clinical Chemistry/Blood Serology. The main difference was found between those in managerial posts (N = 72) and the other MLTs (N = 260). Factor analysis showed three principal components, labelled Professionalism, Work Ethic, and Empathy, but also a different composition of variables of the components for the manager group compared with the non-manager group.
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| 14. |
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| 15. |
- Chong, Ghai Siung, et al.
(författare)
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Tailward Flows in the Vicinity of Fast Earthward Flows
- 2021
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Ingår i: Journal of Geophysical Research - Space Physics. - : Blackwell Publishing. - 2169-9380 .- 2169-9402. ; 126:4
-
Tidskriftsartikel (refereegranskat)abstract
- The occurrence of tailward flows in the magnetotail plasma sheet is closely linked to the dynamics of earthward bursty bulk flows (BBFs). Tailward flows that are observed in the vicinity of these BBFs (or TWABs – Tailward flows around BBFs) may hold unique information on its origin. In this study, we conduct a statistical survey on TWABs by using data from the Cluster mission. We find that TWABs are observed in the vicinity of ∼75% of the BBFs and their occurrence does not depend on BBF velocity magnitude. TWABs have a flow convection pattern consistent with the general tailward flows (GTWs) in the plasma sheet and they do not resemble vortical-like flows. However, TWABs have a flow velocity magnitude twice larger than the GTWs. The plasma density and temperature of TWABs are comparable with BBFs. It is more common to observe a TWAB succeeding than preceding a BBF. However, there is no distinctive difference (in flow pattern, plasma density and temperature) between preceding and succeeding TWABs. We suggest that TWABs are likely the “freshly” rebounded BBFs from the near-Earth region where the magnetic field is stronger. TWABs may represent the early stage of the evolution of tailward flows in the plasma sheet. We also discuss and argue that other mechanisms such as shear-induced vortical flows and tailward slipping of depleted flux tubes cannot be the principal causes of TWABs.
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| 16. |
- Diermeier, T. A., et al.
(författare)
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Treatment after ACL injury: Panther Symposium ACL Treatment Consensus Group
- 2021
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Ingår i: British Journal of Sports Medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 55:1, s. 14-22
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Tidskriftsartikel (refereegranskat)abstract
- Treatment strategies for ACL injuries continue to evolve. Evidence supporting best practice guidelines to manage ACL injury is largely based on studies with low-level evidence. An international consensus group of experts was convened determine consensus regarding best available evidence on operative versus non-operative treatment for ACL injury. The purpose of this study is to report the consensus statements on operative versus non-operative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. Sixty-six international experts on the management of ACL injuries, representing 18 countries, convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the Scientific Organising Committee and Session Chairs. Panel participants reviewed preliminary statements prior to the meeting and provided initial agreement and comments on the statement via online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Eighty per cent agreement was defined a priori as consensus. A total of 11 of 13 statements on operative versus non-operative treatment of ACL injury reached consensus during the Symposium. Nine statements achieved unanimous support, two reached strong consensus, one did not achieve consensus, and one was removed due to redundancy in the information provided. In highly active patients engaged in jumping, cutting and pivoting sports, early anatomical ACL reconstruction is recommended due to the high risk of secondary meniscus and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight plane activities, non-operative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability, or when episodes of giving way occur, anatomical ACL reconstruction is indicated. The consensus statements derived from international leaders in the field may assist clinicians in deciding between operative and non-operative treatment with patients after an ACL injury.
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| 17. |
- Diermeier, T., et al.
(författare)
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Treatment after anterior cruciate ligament injury: Panther Symposium ACL Treatment Consensus Group
- 2020
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Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 28, s. 2390-2402
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Tidskriftsartikel (refereegranskat)abstract
- Treatment strategies for anterior cruciate ligament (ACL) injuries continue to evolve. Evidence supporting best practice guidelines for the management of ACL injury is to a large extent based on studies with low-level evidence. An international consensus group of experts was convened to collaboratively advance toward consensus opinions regarding the best available evidence on operative vs. non-operative treatment for ACL injury. The purpose of this study is to report the consensus statements on operative vs. non-operative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. Sixty-six international experts on the management of ACL injuries, representing 18 countries, were convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the Scientific Organizing Committee and Session Chairs for the three working groups. Panel participants reviewed preliminary statements prior to the meeting and provided the initial agreement and comments on the statement via an online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Eighty percent agreement was defined a-priori as consensus. A total of 11 of 13 statements on operative v. non-operative treatment of ACL injury reached the consensus during the Symposium. Nine statements achieved unanimous support, two reached strong consensus, one did not achieve consensus, and one was removed due to redundancy in the information provided. In highly active patients engaged in jumping, cutting, and pivoting sports, early anatomic ACL reconstruction is recommended due to the high risk of secondary meniscus and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight plane activities, non-operative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability, or when episodes of giving way occur, anatomic ACL reconstruction is indicated. The consensus statements derived from international leaders in the field will assist clinicians in deciding between operative and non-operative treatments with patients after an ACL injury. Level of evidence V. © 2020, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).
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| 18. |
- Diermeier, T., et al.
(författare)
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Treatment after anterior cruciate ligament injury: Panther Symposium ACL Treatment Consensus Group
- 2021
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Ingår i: Journal of Isakos Joint Disorders & Orthopaedic Sports Medicine. - : Elsevier BV. - 2059-7754. ; 6:3, s. 129-137
-
Tidskriftsartikel (refereegranskat)abstract
- Treatment strategies for anterior cruciate ligament (ACL) injuries continue to evolve. Evidence supporting best practice guidelines for the management of ACL injury is to a large extent based on studies with low-level evidence. An international consensus group of experts was convened to collaboratively advance towards consensus opinions regarding the best available evidence on operative versus non-operative treatment for ACL injury. The purpose of this study was to report the consensus statements on operative versus non-operative treatment of ACL injuries developed at the ACL Consensus Meeting Panther Symposium 2019. Sixty-six international experts on the management of ACL injuries, representing 18 countries, convened and participated in a process based on the Delphi method of achieving consensus. Proposed consensus statements were drafted by the Scientific Organising Committee and Session Chairs for the three working groups. Panel participants reviewed preliminary statements prior to the meeting and provided initial agreement and comments on the statement via online survey. During the meeting, discussion and debate occurred for each statement, after which a final vote was then held. Eighty per cent agreement was defined a priori as consensus. A total of 11 of 13 statements on operative veresus non-operative treatment of ACL injury reached consensus during the symposium. Nine statements achieved unanimous support; two reached strong consensus; one did not achieve consensus; and one was removed due to redundancy in the information provided. In highly active patients engaged in jumping, cutting and pivoting sports, early anatomical anterior cruciate ligament reconstruction (ACLR) is recommended due to the high risk of secondary meniscus and cartilage injuries with delayed surgery, although a period of progressive rehabilitation to resolve impairments and improve neuromuscular function is recommended. For patients who seek to return to straight plane activities, non-operative treatment with structured, progressive rehabilitation is an acceptable treatment option. However, with persistent functional instability or when episodes of giving way occur, anatomical ACLR is indicated. The consensus statements derived from international leaders in the field will assist clinicians in deciding between operative and non-operative treatment with patients after an ACL injury. Level of evidence: V
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| 19. |
- Fu, H. S., et al.
(författare)
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Dipolarization fronts as a consequence of transient reconnection : in situ evidence
- 2013
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Ingår i: Geophysical Research Letters. - : American Geophysical Union. - 0094-8276 .- 1944-8007. ; 40:23, s. 6023-6027
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Tidskriftsartikel (refereegranskat)abstract
- Dipolarization fronts (DFs) are frequently detected in the Earth's magnetotail from X-GSM=-30 R-E to X-GSM=-7 R-E. How these DFs are formed is still poorly understood. Three possible mechanisms have been suggested in previous simulations: (1) jet braking, (2) transient reconnection, and (3) spontaneous formation. Among these three mechanisms, the first has been verified by using spacecraft observation, while the second and third have not. In this study, we show Cluster observation of DFs inside reconnection diffusion region. This observation provides in situ evidence of the second mechanism: Transient reconnection can produce DFs. We suggest that the DFs detected in the near-Earth region (X-GSM>-10 R-E) are primarily attributed to jet braking, while the DFs detected in the mid- or far-tail region (X-GSM<-15 R-E) are primarily attributed to transient reconnection or spontaneous formation. In the jet-braking mechanism, the high-speed flow pushes the preexisting plasmas to produce the DF so that there is causality between high-speed flow and DF. In the transient-reconnection mechanism, there is no causality between high-speed flow and DF, because the frozen-in condition is violated.
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| 20. |
- Goncharov, Oleksandr, et al.
(författare)
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Evolution of High-Speed Jets and Plasmoids Downstream of the Quasi-Perpendicular Bow Shock
- 2020
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Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 125:6
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Tidskriftsartikel (refereegranskat)abstract
- Plasma structures with enhanced dynamic pressure, density, or speed are often observed in Earth's magnetosheath. We present a statistical study of these structures, known as jets and fast plasmoids, in the magnetosheath, downstream of both the quasi-perpendicular and quasi-parallel bow shocks. Using measurements from the four Magnetospheric Multiscale (MMS) spacecraft and OMNI solar wind data from 2015-2017, we present observations of jets during different upstream conditions and in the wide range of distances from the bow shock. Jets observed downstream of the quasi-parallel bow shock are seen to propagate deeper and faster into the magnetosheath and on toward the magnetopause. We estimate the shape of the structures by treating the leading edge as a shock surface, and the result is that the jets are elongated in the direction of propagation but also that they expand more quickly in the perpendicular direction as they propagate through the magnetosheath.
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| 21. |
- Hagey, DW, et al.
(författare)
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Myeloid cells from Langerhans cell histiocytosis patients exhibit increased vesicle trafficking and an altered secretome capable of activating NK cells
- 2023
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 108:9, s. 2422-2434
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Tidskriftsartikel (refereegranskat)abstract
- Langerhans cell histiocytosis (LCH) is a potentially life-threatening inflammatory myeloid neoplasia linked to paediatric neurodegeneration, whereby transformed LCH cells form agglomerated lesions in various organs. Although MAP-kinase pathway mutations have been identified in LCH cells, the functional consequences of these mutations and the mechanisms that cause the pathogenic behaviour of LCH cells are not well understood. In our study, we used an in vitro differentiation system and RNA-sequencing to compare monocyte-derived dendritic cells from LCH patients to those derived from healthy controls or patients with Crohn’s disease, a non-histiocytic inflammatory disease. We observed that Interferon-γ treatment exacerbated intrinsic differences between LCH patient and control cells, including strikingly increased endoand exocytosis gene activity in LCH patients. We validated these transcriptional patterns in lesions and functionally confirmed that LCH cells exhibited increased endo- and exocytosis. Furthermore, RNA-sequencing of extracellular vesicles (EV) revealed the enrichment of pathological transcripts involved in cell adhesion, MAP-kinase pathway, vesicle trafficking and T-cell activation in LCH patients. Thus, we tested the effect of the LCH secretome on lymphocyte activity and found significant activation of NK cells. These findings implicate EVs in the pathology of LCH for the first time, in line with their established roles in the formation of various other tumour niches. Thus, we describe novel traits of LCH patient cells and suggest a pathogenic mechanism of potential therapeutic and diagnostic importance.
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| 22. |
- Hagey, DW, et al.
(författare)
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Myeloid cells from Langerhans cell histiocytosis patients exhibit increased vesicle trafficking and an altered secretome capable of activating NK cells
- 2023
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 1592-8721 .- 0390-6078. ; 108:9, s. 2422-2434
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Tidskriftsartikel (refereegranskat)abstract
- Langerhans cell histiocytosis (LCH) is a potentially life-threatening inflammatory myeloid neoplasia linked to paediatric neurodegeneration, whereby transformed LCH cells form agglomerated lesions in various organs. Although MAP-kinase pathway mutations have been identified in LCH cells, the functional consequences of these mutations and the mechanisms that cause the pathogenic behaviour of LCH cells are not well understood. In our study, we used an in vitro differentiation system and RNA-sequencing to compare monocyte-derived dendritic cells from LCH patients to those derived from healthy controls or patients with Crohn’s disease, a non-histiocytic inflammatory disease. We observed that Interferon-γ treatment exacerbated intrinsic differences between LCH patient and control cells, including strikingly increased endoand exocytosis gene activity in LCH patients. We validated these transcriptional patterns in lesions and functionally confirmed that LCH cells exhibited increased endo- and exocytosis. Furthermore, RNA-sequencing of extracellular vesicles (EV) revealed the enrichment of pathological transcripts involved in cell adhesion, MAP-kinase pathway, vesicle trafficking and T-cell activation in LCH patients. Thus, we tested the effect of the LCH secretome on lymphocyte activity and found significant activation of NK cells. These findings implicate EVs in the pathology of LCH for the first time, in line with their established roles in the formation of various other tumour niches. Thus, we describe novel traits of LCH patient cells and suggest a pathogenic mechanism of potential therapeutic and diagnostic importance.
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| 23. |
- Hamrin, Kerstin, et al.
(författare)
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Prolonged Exercise-Induced Stimulation of Skeletal Muscle Glucose Uptake Is due to Sustained Increases in Tissue Perfusion and Fractional Glucose Extraction
- 2011
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 96:4, s. 1085-1092
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Tidskriftsartikel (refereegranskat)abstract
- Context: The mechanisms behind the positive effects of physical activity on glucose metabolism in skeletal muscle and the time course of the effects need to be more elucidated. Objective: The aim was to examine the prolonged effects of an acute bout of one-legged exercise on local skeletal muscle glucose utilization and tissue perfusion. Design and Setting: Interstitial glucose concentration, local tissue perfusion, glucose uptake, and effects of insulin infusion were studied 12 h after an acute bout of exercise and without prior exercise. Participants: Ten healthy subjects, five women and five men, participated in the study. Intervention: Microdialysis measurements, (133)Xe clearance, and a 2-h hyperinsulinemic euglycemic clamp were performed on two occasions. Main Outcome Measures: We measured interstitial glucose concentration and tissue perfusion in the quadriceps femoris muscle of both legs. Results: Tissue perfusion (3.3 +/- 0.6 ml x 100 g(-1) x min(-1) vs. 1.4 +/- 0.2 ml x 100 g(-1) x min(-1); P = 0.007) and basal glucose uptake (2.3 +/- 0.5 mu mol x 100 g(-1) x min(-1) vs. 0.9 +/- 0.2 mu mol x 100 g(-1) x min(-1); P = 0.006) were increased in the leg that had exercised compared to the resting leg; the findings in the resting leg were comparable to those in the control experiment without prior exercise. The relative effect of insulin on fractional skeletal muscle glucose uptake was the same in all experimental settings, and insulin did not affect tissue perfusion. Conclusions: The prolonged stimulatory effect of physical exercise on skeletal muscle glucose uptake was mediated via vascular effects combined with an increase in basal glucose transport independent of enhancement of insulin responses.
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| 24. |
- Hamrin, Maria, 1972-, et al.
(författare)
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Can Reconnection be Triggered as a Solar Wind Directional Discontinuity Crosses the Bow Shock? : A Case of Asymmetric Reconnection
- 2019
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Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 124:11, s. 8507-8523
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Tidskriftsartikel (refereegranskat)abstract
- Here we present some unique observations of reconnection at a quasi-perpendicular bow shock as an interplanetary directional discontinuity (DD) is crossing it simultaneously with the Magnetospheric Multiscale (MMS) mission. There are no burst data, but available data show indications of ongoing reconnection at the shock southward of MMS: a bifurcated current sheet with signatures of Hall magnetic and electric fields, normal magnetic fields indicating a magnetic connection between the two reconnecting regions, field-aligned currents and electric fields, E . J > 0 indicating a conversion of magnetic to kinetic energy, and subspin resolution ion energy-time spectrograms indicating ions being accelerated away from the X-line. The DD is also observed by four upstream spacecraft (ACE, WIND, Geotail, and ARTEMIS P1) and one downstream in the magnetosheath (Cluster 4), but none of them resolve signatures of ongoing reconnection. We therefore suggest that reconnection was temporarily triggered as the DD was compressed by the shock. Reconnection at the bow shock is inevitably asymmetric with both the density and magnetic field strength being higher on one side of the X-line (magnetosheath side) than on the other side where the plasma flow also is supersonic (solar wind side). This is different from the asymmetry exhibited at the more commonly studied case of asymmetric reconnection at the magnetopause. Asymmetric reconnection of the bow shock type has never been studied before, and the data discussed here present some first indications of the properties of the reconnection region for this type of reconnection.
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| 25. |
- Hamrin, Maria, et al.
(författare)
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Observations of concentrated generator regions in the nightside magnetosphere by Cluster/FAST conjunctions
- 2006
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 24, s. 637-49
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Tidskriftsartikel (refereegranskat)abstract
- Here and in the companion paper, Marghitu et al. (2006), we investigate plausible auroral generator regions in the nightside auroral magnetosphere. In this article we use magnetically conjugate data from the Cluster and the FAST satellites during a 3.5-h long event from 19-20 September 2001. Cluster is in the Southern Hemisphere close to apogee, where it probes the plasma sheet and lobe at an altitude of about 18 RE. FAST is below the acceleration region at approximately 0.6 RE. Searching for clear signatures of negative power densities, E(.)J < O, in the Cluster data we can identify three concentrated generator regions (CGRs) during our event. From the magnetically conjugate FAST data we see that the observed generator regions in the Cluster data correlate with auroral precipitation. The downward Poynting flux observed by Cluster, as well as the scale size of the CGRs, are consistent with the electron energy flux and the size of the inverted-V regions observed by FAST. To our knowledge, these are the first in-situ observations of the crossing of an auroral generator region. The main contribution to E(.)J < O comes from the GSE E(y)J(y). The electric field E-y is weakly negative during most of our entire event and we conclude that the CGRs occur when the duskward current J(y) grows large and positive. We find that our observations are consistent with a local southward expansion of the plasma sheet and/or rather complicated, 3-D wavy structures propagating over the Cluster satellites. We find that the plasma is working against the magnetic field, and that kinetic energy is being converted into electromagnetic energy. Some of the energy is transported away as Poynting flux.
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| 26. |
- Hamrin, Maria, et al.
(författare)
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The evolution of flux pileup regions in the plasma sheet : Cluster observations
- 2013
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Ingår i: Journal of Geophysical Research. - : American Geophysical Union (AGU). - 0148-0227 .- 2156-2202 .- 2169-9380 .- 2169-9402. ; 118:10, s. 6279-6290
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Tidskriftsartikel (refereegranskat)abstract
- Bursty bulk flows (BBFs) play an important role for the mass, energy, and magnetic flux transport in the plasma sheet, and the flow pattern in and around a BBF has important consequences for the localized energy conversion between the electromagnetic and plasma mechanical energy forms. The plasma flow signature in and around BBFs is often rather complicated. Return flows and plasma vortices are expected to exist at the flanks of the main flow channel, especially near the inner plasma sheet boundary, but also farther down-tail. A dipolarization front (DF) is often observed at the leading edge of a BBF, and a flux pileup region (FPR) behind the DF. Here we present Cluster data of three FPRs associated with vortex flows observed in the midtail plasma sheet on 15 August 2001. According to the principles of Fu et al. (2011, 2012c), two of the FPRs are considered to be in an early stage of evolution (growing FPRs). The third FPR is in a later stage of evolution (decaying FPR). For the first time, the detailed energy conversion properties during various stages of the FPR evolution have been measured. We show that the later stage FPR has a more complex vortex pattern than the two earlier stage FPRs. The two early stage FPR correspond to generators, EJ<0, while the later stage FPR only shows weak generator characteristics and is instead dominated by load signatures at the DF, EJ>0. Moreover, to our knowledge, this is one of the first times BBF-related plasma vortices have been observed to propagate over the spacecraft in the midtail plasma sheet at geocentric distances of about 18R(E). Our observations are compared to recent simulation results and previous observations.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- Horvath, Alexandra, et al.
(författare)
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Treatment of Primary Dorsal Wrist Ganglion-A Systematic Review
- 2022
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Ingår i: JOURNAL OF WRIST SURGERY. - : Georg Thieme Verlag KG. - 2163-3916 .- 2163-3924. ; 12:2, s. 177-190
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Tidskriftsartikel (refereegranskat)abstract
- Purpose The aim of this study was to compare the rates of recurrence and wound infection in patients with primary dorsal wrist ganglion treated with aspiration (with or without an injection of an additive), open excision, or arthroscopic resection. Methods This systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered on PROSPERO. Systematic electronic searches in PubMed (MEDLINE), EMBASE, Web of Science, and the Cochrane Library of Controlled Trials were performed on May 5, 2020, and June 1, 2021, respectively. All clinical studies written in English determining the recurrence and wound infection rates after treatment of primary dorsal wrist ganglion with aspiration, open excision, or arthroscopic resection in patients over the age of 16 years were eligible for inclusion. Quality assessment was guided by the Cochrane Collaboration's tool for randomized controlled trials (RCTs) and the methodological index for nonrandomized studies (MINORS) tool for observational studies. Results The literature searches resulted in 1,691 studies. After screening, five RCTs, enrolling 233 patients, and six observational studies, enrolling 316 patients with primary dorsal wrist ganglions were included. Quality assessment of the included RCTs and observational studies determined the existing level of evidence pertaining to primary dorsal wrist ganglion treatment to be low. About 11 studies reported on recurrence rate, which ranged between 7 and 72% for patients initially treated with aspiration (with or without an injection of an additive). In comparison, the recurrence rate for the open excision and arthroscopic resection groups ranged between 6 to 41% and 0 to 16%, respectively. Four studies investigated wound-related complications, for which zero infections were reported, irrespective of treatment. Conclusion The evidence summarized in this systematic review demonstrates a considerable variability in recurrence rate following aspiration and open or arthroscopic resection of a primary dorsal wrist ganglion. The greatest variability in recurrence was displayed among studies on aspiration. The overall infection rate after treatment of dorsal wrist ganglions seems to be low regardless of the treatment type. However, the divergent results of individual studies highlight a pressing need for prospective controlled trials assessing outcomes following dorsal wrist ganglion treatment.
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| 33. |
- Langhorne, P, et al.
(författare)
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Is stroke unit care portable? A systematic review of the clinical trials
- 2005
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Ingår i: Age and Ageing. - : Oxford University Press (OUP). - 0002-0729 .- 1468-2834. ; 34:4, s. 324-330
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is not known if mobile stroke teams can achieve the good results seen in trials of geographically discrete stroke wards (stroke units). Objective: To establish the effectiveness of mobile stroke teams. Design: Systematic review of controlled clinical trials that compared peripatetic systems of organised stroke care (stroke team care) with alternative hospital services. Methods: Systematic review and meta-analysis (using Cochrane Collaboration methodology and involving the primary trialists). Clinical outcomes included death, dependency, the need for institutional care and measures of the process of care such as the delivery of key investigations and treatments. Results: Six clinical trials (1,085 patients) were identified, five (781 patients) compared some form of stroke team care with conventional care in general medical wards and one (304 patients) compared team care with a comprehensive stroke unit. Compared with care in general wards, stroke team care improved some aspects of the process of care, but clinical outcomes were similar. Compared with a comprehensive stroke unit, stroke team patients were significantly less likely to survive (P< 0.001), return home (P< 0.001) or regain independence (P< 0.0001). Most aspects of the process of care were also poorer than in the stroke unit. Conclusions: Care from a mobile stroke team had no major impact on death, dependency or the need for institutional care. © The Author 2005. Published by Oxford University Press. All rights reserved.
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| 34. |
- Larsson, Per, et al.
(författare)
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Factors determining the uptake of persistent pollutants in an eel population (Anguilla anguilla L.) of a eutrophic lake
- 1991
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Ingår i: Environmental Pollution. - 0269-7491 .- 1873-6424. ; 69:1, s. 39-50
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Tidskriftsartikel (refereegranskat)abstract
- The distribution of persistent pollutants in an eel population from a eutrophic lake of southern Scandinavia was examined. The origin of PCBs, DDT, DDE and lindane found in the fish was most likely the atmosphere. The most important factors for uptake of the chlorinated hydrocarbons was age (exposure time), growth rate and fat content. The life cycle of the eel is unique with a stage in freshwater when energy reserves (fat stored in muscular tissue) and lipophilic pollutants are accumulated. This stage is followed by a long migration to the spawning areas in the Sargasso Sea when pollutants are released from the fat deposits. These two stages followed by a once-in-a-lifetime spawning behaviour, makes the eel especially vulnerable to persistent pollutants. The effects of persistent pollutants combined with the eel's unusual life cycle may explain the decline in the eel population in northern Europe in recent decades.
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| 35. |
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| 36. |
- Lindkvist, Jesper, 1986-, et al.
(författare)
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Energy conversion in cometary atmospheres Hybrid modeling of 67P/Churyumov-Gerasimenko
- 2018
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 616
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Tidskriftsartikel (refereegranskat)abstract
- Aims. We wish to investigate the energy conversion between particles and electromagnetic fields and determine the location where it occurs in the plasma environment of comets. Methods. We used a hybrid plasma model that included photoionization, and we considered two cases of the solar extreme ultraviolet flux. Other parameters corresponded to the conditions of comet 67P/Churyumov-Gerasimenko at a heliocentric distance of 1.5 AU. Results. We find that a shock-like structure is formed upstream of the comet and acts as an electromagnetic generator, similar to the bow shock at Earth that slows down the solar wind. The Poynting flux transports electromagnetic energy toward the inner coma, where newly born cometary ions are accelerated. Upstream of the shock-like structure, we find local energy transfer from solar wind ions to cometary ions. We show that mass loading can be a local process with a direct transfer of energy, but also part of a dynamo system with electromagnetic generators and loads. Conclusions. The energization of cometary ions is governed by a dynamo system for weak ionization, but changes into a large conversion region with local transfer of energy directly from solar wind protons for high ionization.
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| 37. |
- Lindman, Ida, et al.
(författare)
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Evaluation of outcome reporting trends for femoroacetabular impingement syndrome- a systematic review
- 2021
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Ingår i: Journal of Experimental Orthopaedics. - : Springer Science and Business Media LLC. - 2197-1153. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aim of this systematic review was to evaluate the trends in the literature regarding surgical treatment for femoroacetabular impingement syndrome (FAIS) and to present which patient-reported outcome-measures (PROMs) and surgical approaches are included. Methods: This systematic review was conducted with the PRISMA guidelines. The literature search was performed on PubMed and Embase, covering studies from 1999 to 2020. Inclusion criteria were clinical studies with surgical treatment for FAIS, the use of PROMs as evaluation tool and studies in English. Exclusion criteria were studies with patients < 18years, cohorts with < 8 patients, studies with primarily purpose to evaluate other diagnoses than FAIS and studies with radiographs as only outcomes without using PROMs. Data extracted were author, year, surgical intervention, type of study, level of evidence, demographics of included patients, and PROMs. Results: The initial search yielded 2,559 studies, of which 196 were included. There was an increase of 2,043% in the number of studies from the first to the last five years (2004–2008)—(2016–2020). There were 135 (69%) retrospective, 55 (28%) prospective and 6 (3%) Randomized Controlled Trials. Level of evidence ranged from I-IV where Level III was most common (44%). More than half of the studies (58%) originated from USA. Arthroscopic surgery was the most common surgical treatment (85%). Mean follow-up was 27.0months (± 17 SD), (range 1.5–120months). Between 1–10 PROMs were included, and the modified Harris Hip Score (mHHS) was most commonly used (61%). Conclusion: There has been a continuous increase in the number of published studies regarding FAIS with the majority evaluating arthroscopic surgery. The mHHS remains being the most commonly used PROM. © 2021, The Author(s).
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| 38. |
- Persson, Moa, et al.
(författare)
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H+/O+ Escape Rate Ratio in the Venus Magnetotail and its Dependence on the Solar Cycle
- 2018
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Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 45:20, s. 10805-10811
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Tidskriftsartikel (refereegranskat)abstract
- A fundamental question for the atmospheric evolution of Venus is how much water-related material escapes from Venus to space. In this study, we calculate the nonthermal escape of H+ and O+ ions through the Venusian magnetotail and its dependence on the solar cycle. We separate 8 years of data obtained from the ion mass analyzer on Venus Express into solar minimum and maximum. The average escape of H+ decreased from 7.6.10(24) (solar minimum) to 2.1.10(24) s(-1) (solar maximum), while a smaller decrease was found for O+: 2.9.10(24) to 2.0.10(24) s(-1). As a result, the H+/O+ flux ratio decreases from 2.6 to 1.1. This implies that the escape of hydrogen and oxygen could have been below the stoichiometric ratio of water for Venus in its early history under the more active Sun.
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| 39. |
- Persson, Moa, et al.
(författare)
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The Venusian Atmospheric Oxygen Ion Escape : Extrapolation to the Early Solar System
- 2020
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Ingår i: Journal of Geophysical Research - Planets. - : American Geophysical Union (AGU). - 2169-9097 .- 2169-9100. ; 125:3
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Tidskriftsartikel (refereegranskat)abstract
- The present atmosphere of Venus contains almost no water, but recent measurements indicate that in its early history, Venus had an Earth-like ocean. Understanding how the Venusian atmosphere evolved is important not only for Venus itself but also for understanding the evolution of other planetary atmospheres. In this study, we quantify the escape rates of oxygen ions from the present Venus to infer the past of the Venusian atmosphere. We show that an extrapolation of the current escape rates back in time leads to the total escape of 0.02-0.6 m of a global equivalent layer of water. This implies that the loss of ions to space, inferred from the present state, cannot account for the loss of an historical Earth-like ocean. We find that the O+ escape rate increases with solar wind energy flux, where more energy available leads to a higher escape rate. Oppositely, the escape rate decreases slightly with increased extreme ultraviolet radiation (EUV) flux, though the small variation of EUV flux over the measured solar cycle may explain the weak dependency. These results indicate that there is not enough energy transferred from the solar wind to Venus' upper atmosphere that can lead to the escape of the atmosphere over the past 3.9 billion years. This means that the Venusian atmosphere did not have as much water in its atmosphere as previously assumed or the present-day escape rates do not represent the historical escape rates at Venus. Otherwise, some other mechanisms have acted to more effectively remove the water from the Venusian atmosphere. Plain Language Summary Today, Venus only has small amounts of water in its atmosphere. In its early history, Venus presumably contained an Earth-like ocean of several meters. The evolution of the atmosphere may have been caused by escape of atmospheric content to space. In this study, we investigate how much the escape of oxygen ions to space could have affected the atmospheric evolution for Venus from measurements of the present-day escape rates. Using measurements of oxygen ions in the vicinity of Venus, we show that the amount of energy available in the solar wind to be transferred to the upper atmosphere of Venus determines how much of the atmosphere escapes. From the evolution of the energy in the solar wind over the past 3.9 billion years, together with the relation between the solar wind energy and oxygen ion escape, we show that in total, about 0.02-0.6 m of water depth, if spread equally over the entire Venusian surface, was lost. This indicates that either Venus did not have as much water as previously assumed or the current escape rates are not representative of the historical escape rates. Otherwise, some other mechanisms must have acted to more effectively remove the water from Venus.
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| 40. |
- Pettersson, N., et al.
(författare)
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The prevalence of chronic musculoskeletal pain in patients with ulcerative colitis in comparison to controls from the general population : a cross-sectional study
- 2020
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ Publishing Group Ltd. - 0003-4967 .- 1468-2060. ; 79, s. 474-474
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Musculoskeletal symptoms are common in patients with ulcerative colitis (UC) but the knowledge of the prevalence of chronic regional pain (ChRP) and chronic widespread pain (ChWP) in patients with UC is scarce.Objectives:To compare the prevalence of ChRP, ChWP and chronic pain in different body locations in patients with UC with controls from the general population and to investigate if disease activity in UC is related to chronic pain.Methods:From a national inflammatory bowel disease (IBD) Register (SWIBREG), all living patients with a confirmed UC diagnosis, aged 20-74 years (n=1134), who were residents in two counties in Northern Sweden were posted a validated questionnaire. Persons from the general population from a previous study (1) using the same questionnaires was used as controls (n=3867). The questionnaire comprises demography, history of pain and body localisation of pain. The disease activity of UC was measured by Patient- Simple Clinical Colitis Activity Index (P-SCCAI). ChRP and ChWP was defined as having pain for at least three months the last year. ChWP was defined as having pain on both left and right side of the body and both above and below the waist, and in the axial part of the body.Results:The response rate for the patients with UC was 49.0% and for the controls 62.7%. The patients were older than the controls (mean age 52.8 vs 46.5 years; p<0.001) but there was no difference in gender (men 50.5% vs 46.7%; p=0.086). The reported prevalence of any chronic pain, ChRP and ChWP was higher in patients with UC versus controls (54.4% vs 39.5%; p<0.001; 32.5% vs 24.2%; p<0.001 and 19.4% vs 12.5%; p<0.001). The differences for reported chronic pain (any pain) was seen in all age groups. The patients with UC reported significantly more pain in the regions “lower back”, “hip/upper leg” and “lower leg/foot” compared to controls (Table). The patients with P-SSCAI >5 (n=121) reported more ChWP than patients with P-SSCAI <5 (n=426) (46.3% vs 12.7%; p<0.001) and controls (46.3% vs 12.5%; p<0.001) with significant differences compared to controls in all body regions. No significant difference in ChWP was found between patients with P-SSCAI <5 and controls (12.7% vs 12.5%; p=0.917). There was a slightly higher prevalence of reported any chronic pain between patients with P-SSCAI <5 and controls (46.5% vs 39.5%; p=0.007).Table.The prevalence of reported chronic musculoskeletal pain in different body regions in patients with ulcerative colitis and controls.Body regionUlcerative colitis (n = 556)Controls (n = 2425)P-valueAnterior chest32 (5.8 %)115 (4.7 %)0.2Neck119 (21.4 %)460 (19.0 %)0.3Dorsal chest63 (11.3 %)236 (9.7 %)0.3Lower back168 (30.2 %)557 (23.0 %)0.0008Shoulder/upper arm126 (22.7 %)482 (20.0 %)0.2Elbow/lower arm/hand103 (18.5 %)405 (16.7 %)0.4Hip/upper leg113 (20.3 %)319 (13.1 %)<0.0001Knee95 (17.1 %)335 (13.8 %)0.07Lower leg/foot97 (17.4 %)300 (12.4 %)0.003Conclusion:Patients with UC reported more chronic pain than controls from the general population, especially from the lower back and hip region. Higher UC disease activity was associated with more pain in all body regions.References:[1]Bergman S, Herrstrom P, Hogstrom K, Petersson IF, Svensson B, Jacobsson LT. Chronic musculoskeletal pain, prevalence rates, and sociodemographic associations in a swedish population study. J Rheumatol 2001;28:1369-77.Disclosure of Interests: :Nina Pettersson: None declared, Fredrik Kragsbjerg: None declared, Arvid Hamrin: None declared, Stefan Bergman: None declared, Helena Forsblad-d’Elia Grant/research support from: Unrestricted grant from Novartis., Consultant of: Advisory Board Fees from Sandoz, Novartis, and Abbvie, Pontus Karling: None declared
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| 41. |
- Pitkänen, Timo, 1979-, et al.
(författare)
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Fast Earthward Convection in the Magnetotail and Nonzero IMF By : MMS Statistics
- 2023
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Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 128:12
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Tidskriftsartikel (refereegranskat)abstract
- We statistically investigate convective earthward fast flows using data measured by the Magnetospheric Multiscale mission in the tail plasma sheet during 2017–2021. We focus on “frozen in” fast flows and investigate the importance of different electric field components in the Sun-Earth (V⊥x) and dusk-dawn (V⊥y) velocity components perpendicular to the magnetic field. We find that a majority of the fast flow events (52% of 429) have the north-south electric field component (Ez) as the most relevant or dominating component whereas 26% are so-called conventional type fast flows with Ey and Ex as the relevant components. The rest of the flow events, 22%, fall into the two ’mixed’ categories, of which almost all these fast flows, 20% of 429, have Ey and Ez important for V⊥x and V⊥y, respectively. There is no Y-location preference for any type of the fast flows. The conventional fast flows are detected rather close to the neutral sheet whereas the other types can be measured farther away. Typical total speeds are highest in the mixed category. Typical perpendicular speeds are comparably high in the conventional and mixed categories. The slowest fast flows are measured in the Ez category. Most of the fast flow events are measured in the substorm recovery phase. Prevailing interplanetary magnetic field By conditions influence the V⊥y direction and the influence is most efficient for the Ez-dominated fast flows.
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| 42. |
- Piussi, R., et al.
(författare)
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Self-Reported Symptoms of Depression and Anxiety After ACL Injury: A Systematic Review
- 2022
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Ingår i: Orthopaedic Journal of Sports Medicine. - : SAGE Publications. - 2325-9671. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Depression and anxiety symptoms can occur in patients following an anterior cruciate ligament (ACL) injury, and the presence of these symptoms has been associated with poorer self-reported knee function in this type of injury. Purpose: To investigate the prevalence and severity of self-reported symptoms of depression and anxiety following an ACL injury. Study Design: Systematic review; Level of evidence, 4. Methods: PubMed, Cochrane Library, Embase, PsycINFO, AMED, and PEDro databases were searched using a combination of keywords relating to ACL, depression, anxiety, and their synonyms. Inclusion criteria were clinical studies written in English that reported on patients with an injured and/or reconstructed ACL and assessed symptoms of depression and/or anxiety. Data extraction was performed independently by 2 authors. Data synthesis was performed using an emergent synthesis approach. The quality of the included studies was assessed using the methodological index for non-randomized studies or the Mixed-Methods Appraisal Tool. Certainty of evidence was determined using the Grading of Recommendations Assessment, Development and Evaluation. Results: After abstract screening, 37 studies were assessed in full text, of which 16 were included. The studies comprised 682 patients (417 male [61%]). The depression symptoms appeared to be more severe in elite athletes compared with recreational athletes. Symptoms decreased over time from moment of ACL reconstruction to up to 2 years postoperatively. The prevalence of self-reported symptoms of anxiety after an ACL injury was reported in 1 study (2%). There were no differences in anxiety symptoms between professional and amateur athletes or between adolescents and adults. The overall quality of the studies was low or very low. Conclusion: Patients who sustain an ACL injury can suffer from symptoms of depression, especially during the first 6 weeks after ACL reconstruction. Depressive symptoms are more common among professional versus nonprofessional athletes. Levels of anxiety symptoms were not above the cutoffs for a diagnosis of anxiety after an ACL injury. © The Author(s) 2022.
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| 43. |
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| 44. |
- Svantesson, Eleonor, et al.
(författare)
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Clinical outcomes after anterior cruciate ligament injury: Panther Symposium ACL Injury Clinical Outcomes Consensus Group
- 2020
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Ingår i: Journal of ISAKOS. - : Elsevier BV. - 2059-7754. ; 5, s. 281-294
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Forskningsöversikt (refereegranskat)abstract
- Purpose: A stringent outcome assessment is a key aspect for establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. The aim of this consensus statement was to establish what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used and at what follow-up time those outcomes should be assessed. Methods: To establish a standardised assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, PA, USA, in June 2019. The group reached consensus on nine statements by using a modified Delphi method. Results: In general, outcomes after ACL treatment can be divided into four robust categories - early adverse events, patient-reported outcomes, ACL graft failure/recurrent ligament disruption, and clinical measures of knee function and structure. A comprehensive assessment following ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained re-injuries, validated knee-specific patient-reported outcomes and Health-Related Quality of Life questionnaires. In the mid-term to long-term follow-up, the presence of osteoarthritis should be evaluated. Conclusion: This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment. Level of Evidence: Level V. © International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine 2020. Re-use permitted under CC BY-NC. No commercial re-use. Published by BMJ.
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| 46. |
- Westin, Olof, et al.
(författare)
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Older Age Predicts Worse Function 1 Year After an Acute Achilles Tendon Rupture: A Prognostic Multicenter Study on 391 Patients
- 2018
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Ingår i: Orthopaedic Journal of Sports Medicine. - : SAGE Publications. - 2325-9671. ; 6:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is limited evidence regarding the patient-related factors that influence treatment outcomes after an acute Achilles tendon rupture. Purpose/Hypothesis: The purpose of this study was to determine the predictors of functional and patient-reported outcomes 1 year after an acute Achilles tendon rupture using a multicenter cohort and to determine patient characteristics for reporting within the top and bottom 10% of the Achilles tendon Total Rupture Score (ATRS) and heel-rise height outcomes. The hypothesis was that older age, greater body mass index (BMI), and female sex would lead to inferior outcomes. Study Design: Cohort study; Level of evidence, 2. Methods: Patients were selected by combining 5 randomized controlled trials from 2 different centers in Sweden. Functional outcomes were assessed using validated heel-rise tests (height, number of repetitions, total work, and concentric power) for muscular endurance and strength, and the relationship between injured and uninjured legs was calculated as the limb symmetry index (LSI). Patient-reported outcomes were measured using the ATRS. All outcomes were collected at the 1-year follow-up. Independent predictors included were patient sex, smoking, BMI, age, and surgical versus nonsurgical treatment. Results: Of the 391 included patients, 307 (79%) were treated surgically. The LSI of heel-rise height at the 1-year follow-up decreased by approximately 4% for every 10-year increment in age (beta, -3.94 [95% CI, -6.19 to -1.69]; P = .0006). In addition, every 10-year increment in age resulted in a 1.79-fold increase in the odds of being in the lowest 10% of the LSI of heel-rise height. Moreover, a nonsignificant superior LSI of heel-rise height was found in patients treated surgically compared with nonsurgical treatment (beta, -4.49 [95% CI, -9.14 to 0.16]; P = .058). No significant predictor was related to the ATRS. Smoking, patient sex, and BMI did not significantly affect the 1-year results for the LSI of the heel-rise tests. Conclusion: Older age at the time of injury negatively affected heel-rise height 1 year after an Achilles tendon rupture. Irrespective of age, a nonsignificant relationship toward the superior recovery of heel-rise height was seen in patients treated surgically. None of the factors studied affected patient-reported outcomes.
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| 47. |
- Yao, S.T., et al.
(författare)
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Ion-Vortex Magnetic Hole With Reversed Field Direction in Earth's Magnetosheath
- 2023
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Ingår i: Journal of Geophysical Research - Space Physics. - : John Wiley & Sons. - 2169-9380 .- 2169-9402. ; 128:7
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Tidskriftsartikel (refereegranskat)abstract
- Plasma vortices are ubiquitous in space and play important roles in the transmission of energy and mass at various scales. For small-scale plasma vortices on the order of ion gyroradius, however, their properties and characteristics remain unclear. Here, we provide unique findings of an ion-scale vortex observed in the Earth's magnetosheath. The vortex is generated by the ion diamagnetic drift associated with an isolated magnetic hole (MH). The magnetic field in the axial direction is reversed in the vortex center, which is consistent with ring-shaped currents carried by the ions. The field strength becomes very weak (<1 nT) at the field reversal region, although the ion distributions vary rather continuously across the entire structure. A kinetic equilibrium model is then applied to reconstruct the above features. These findings can help us understand the plasma vortex and MH from magnetohydrodynamics to kinetic scales.
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