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Sökning: WFRF:(Fatemi Shahab)

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1.
  • Acosta, Stefan, et al. (författare)
  • Prospective Comparison of Plasma Biomarker and Traditional Risk Factor Profiles for Incident Isolated Atherosclerotic Disease and Incident Isolated Abdominal Aortic Aneurysm
  • 2022
  • Ingår i: Frontiers in Cardiovascular Medicine. - : Frontiers Media SA. - 2297-055X. ; 8, s. 1-9
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Traditional risk factors for atherosclerotic disease (AD) are well-known, of which some are relevant also for abdominal aortic aneurysms (AAA). The present study compares the importance of plasma biomarkers and traditional risk factor profiles for incident AD without concomitant AAA (isolated AD) and AAA without concomitant AD (isolated AAA) during long-term follow-up. Methods: In the Malmö Diet and Cancer Study-cardiovascular cohort, 5,381 participants were free from atrial fibrillation or flutter, AD (coronary artery disease, atherothrombotic ischemic stroke, carotid artery disease, or peripheral artery disease), and AAA underwent blood sampling under standardized fasting conditions between 1991 and 1994. Cox proportional hazards regression analysis was used to calculate hazard ratios (HR) with 95% CIs. Results: During a median follow-up of 23.1 years, 1,152 participants developed isolated AD, and 44 developed isolated AAA. Adjusted HR for lipoprotein-associated phospholipase A2 (mass) (HR 1.53, 95% CI 1.14-2.04 vs. HR 1.05, 95% CI.99-1.12) was higher for incident isolated AAA compared to incident isolated AD, respectively. Mid-regional pro-adrenomedullin (MR-proADM) was associated with incident isolated AD (HR 1.17, 95% CI 1.1-1.25) and incident isolated AAA (HR 1.47, 95% CI 1.15-1.88). MR-proADM was correlated (r = 0.32; p < 0.001) to body mass index (BMI), and BMI was associated with increased risk of incident isolated AAA (HR 1.43, 95% CI 1.02-2). No participant with diabetes mellitus (DM) at baseline developed isolated AAA (0/44), whereas DM was associated with an increased risk of isolated AD (HR 2.57, 95% CI 2.08-3.18). Adjusted HR for male sex (HR 4.8, 95% CI 2.42-9.48, vs. HR 1.76, 95% CI 1.56-1.98) and current smoking (HR 4.79, 95% CI 2.42-9.47 vs. HR 1.97, 95% CI 1.73-2.23) were higher in the incident isolated AAA group compared to the incident isolated AD group, respectively. Conclusions: The data supports the view that components of vascular inflammation and cardiovascular stress drives AAA development, whereas glycated cross-links in abdominal aortic wall tissue may have a plausible role in reducing AAA risk in individuals with DM.
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2.
  • Aizawa, S., et al. (författare)
  • Cross-comparison of global simulation models applied to Mercury's dayside magnetosphere
  • 2021
  • Ingår i: Planetary and Space Science. - : Elsevier. - 0032-0633 .- 1873-5088. ; 198
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the first comparison of multiple global simulations of the solar wind interaction with Mercury's dayside magnetosphere, conducted in the framework of the international collaborative project SHOTS - Studies on Hermean magnetosphere Oriented Theories and Simulations. Two 3D magnetohydrodynamic and two 3D hybrid simulation codes are used to investigate the global response of the Hermean magnetosphere without its exosphere to a northward-oriented interplanetary magnetic field. We cross-compare the results of the four codes for a theoretical case and a MESSENGER orbit with similar upstream plasma conditions. The models agree on bowshock and magnetopause locations at 2.1 ​± ​0.11 and 1.4 ​± ​0.1 Mercury planetary radii, respectively. The latter locations may be influenced by subtle differences in the treatment of the plasma boundary at the planetary surface. The predicted magnetosheath thickness varies less between the codes. Finally, we also sample the plasma data along virtual trajectories of BepiColombo's Magnetospheric and Planetary Orbiter. Our ability to accurately predict the structure of the Hermean magnetosphere aids the analysis of the onboard plasma measurements of past and future magnetospheric missions.
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3.
  • Behar, Etienne, et al. (författare)
  • Menura : A code for simulating the interaction between a turbulent solar wind and solar system bodies
  • 2022
  • Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 40:3, s. 281-297
  • Tidskriftsartikel (refereegranskat)abstract
    • Despite the close relationship between planetary science and plasma physics, few advanced numerical tools allow bridging the two topics. The code Menura proposes a breakthrough towards the self-consistent modelling of these overlapping fields, in a novel two-step approach allowing for the global simulation of the interaction between a fully turbulent solar wind and various bodies of the solar system. This article introduces the new code and its two-step global algorithm, illustrated by a first example: the interaction between a turbulent solar wind and a comet.
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4.
  • Dakhel, Ardwan, et al. (författare)
  • Vasoactive Biomarkers Associated With Long-Term Incidence of Symptomatic Peripheral Arterial Disease and Mortality
  • 2021
  • Ingår i: Angiology. - : SAGE Publications. - 0003-3197 .- 1940-1574. ; 72:6, s. 550-555
  • Tidskriftsartikel (refereegranskat)abstract
    • We evaluated if plasma biomarkers can predict incident peripheral arterial disease (PAD) and mortality in a longitudinal cohort study. Men (n = 3618) and women (n = 1542) were included in the Malmö Preventive Project and underwent analysis of: C-terminal endothelin-1 (CT-proET-1), N-Terminal prosomatostatin (NT-proSST), midregional proatrial natriuretic peptide (MR-proANP), procalcitonin (PCT), and copeptin. Participants were followed up for incident PAD and mortality until December 31, 2016. Median follow-up was 11.2 years (interquartile range 9.4-12.2). Cumulative incidence of PAD was 4.3% (221/5160), 4.5% in men (164/3618) and 3.7% in women (57/1542; P =.174). In an adjusted Cox proportional hazards regression model, higher CT-proET-1 (hazard ratio [HR] 1.8; 95% confidence interval [CI] 1.4-2.3), NT-proSST (HR 1.5; 95% CI 1.2-2.0), and MR-proANP (HR 1.7; 95% CI 1.3-2.3) were independently associated with incident PAD, and higher CT-proET-1 (HR 1.3; 95% CI 1.2-1.5), NT-proSST (HR 1.2; 95% CI 1.1-1.3), MR-proANP (HR 1.4; 95% CI 1.3-1.6), PCT (HR 1.1; 95% CI 1.0-1.2), and copeptin (HR 1.2; 95% CI 1.1-1.4) were independently associated with mortality. Increased levels of CT-proET-1, NT-proSST, and MR-proANP were independently associated with incident PAD, whereas all the vasoactive biomarkers were independently associated with mortality during follow-up.
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5.
  • Dhanaya, M. B., et al. (författare)
  • Proton entry into the near-lunar plasma wake for magnetic field aligned flow
  • 2013
  • Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 40:2, s. 2913-2917
  • Tidskriftsartikel (refereegranskat)abstract
    • We report the first observation of protons in the near-lunar (100–200 km from the surface) and deeper (near anti-subsolar point) plasma wake when the interplanetary magnetic field (IMF) and solar wind velocity (vsw) are parallel (aligned flow; angle between IMF and vsw≤10°). More than 98% of the observations during aligned flow condition showed the presence of protons in the wake. These observations are obtained by the Solar Wind Monitor sensor of the Sub-keV Atom Reflecting Analyser experiment on Chandrayaan-1. The observation cannot be explained by the conventional fluid models for aligned flow. Back tracing of the observed protons suggests that their source is the solar wind. The larger gyroradii of the wake protons compared to that of solar wind suggest that they were part of the tail of the solar wind velocity distribution function. Such protons could enter the wake due to their large gyroradii even when the flow is aligned to IMF. However, the wake boundary electric field may also play a role in the entry of the protons into the wake.
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6.
  • Farrell, William M., et al. (författare)
  • The dust, atmosphere, and plasma at the moon
  • 2024
  • Ingår i: Reviews in Mineralogy and Geochemistry, Mineralogical Society of America. - : Walter de Gruyter. - 1529-6466 .- 1943-2666. ; 89, s. 563-609
  • Tidskriftsartikel (refereegranskat)
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7.
  • Fatemi, Shahab, et al. (författare)
  • A modelling approach to infer the solar wind dynamic pressure from magnetic field observations inside Mercury's magnetosphere
  • 2018
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 614
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims: The lack of an upstream solar wind plasma monitor when a spacecraft is inside the highly dynamic magnetosphere of Mercury limits interpretations of observed magnetospheric phenomena and their correlations with upstream solar wind variations.Methods: We used AMITIS, a three-dimensional GPU-based hybrid model of plasma (particle ions and fluid electrons) to infer the solar wind dynamic pressure and Alfvén Mach number upstream of Mercury by comparing our simulation results with MESSENGER magnetic field observations inside the magnetosphere of Mercury. We selected a few orbits of MESSENGER that have been analysed and compared with hybrid simulations before. Then we ran a number of simulations for each orbit (~30–50 runs) and examined the effects of the upstream solar wind plasma variations on the magnetic fields observed along the trajectory of MESSENGER to find the best agreement between our simulations and observations.Results: We show that, on average, the solar wind dynamic pressure for the selected orbits is slightly lower than the typical estimated dynamic pressure near the orbit of Mercury. However, we show that there is a good agreement between our hybrid simulation results and MESSENGER observations for our estimated solar wind parameters. We also compare the solar wind dynamic pressure inferred from our model with those predicted previously by the WSA-ENLIL model upstream of Mercury, and discuss the agreements and disagreements between the two model predictions. We show that the magnetosphere of Mercury is highly dynamic and controlled by the solar wind plasma and interplanetary magnetic field. In addition, in agreement with previous observations, our simulations show that there are quasi-trapped particles and a partial ring current-like structure in the nightside magnetosphere of Mercury, more evident during a northward interplanetary magnetic field (IMF). We also use our simulations to examine the correlation between the solar wind dynamic pressure and stand-off distance of the magnetopause and compare it with MESSENGER observations. We show that our model results are in good agreement with the response of the magnetopause to the solar wind dynamic pressure, even during extreme solar events. We also show that our model can be used as a virtual solar wind monitor near the orbit of Mercury and this has important implications for interpretation of observations by MESSENGER and the future ESA/JAXA mission to Mercury, BepiColombo.
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8.
  • Fatemi, Shahab, et al. (författare)
  • Circulating Biomarkers Predict Symptomatic but Not Asymptomatic Carotid Artery Stenosis
  • 2022
  • Ingår i: Cerebrovascular Diseases. - : S. Karger AG. - 1015-9770 .- 1421-9786. ; 51:5, s. 623-629
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Subjects exposed to risk factors such as age, gender, hypertension, diabetes mellitus, and smoking are prone to atherosclerotic events. Aims: The main aim of this longitudinal cohort study was to determine whether the role of novel plasma biomarkers for atherosclerotic carotid artery disease is different in subjects developing symptomatic carotid artery stenosis (CAS), as opposed to those with incident asymptomatic CAS. Methods: The following biomarkers were measured in 5,550 middle-aged subjects in a population-based cohort study: C-reactive protein (CRP), lipoprotein-associated phospholipase A2 mass and activity, proneurotensin, midregional proadrenomedullin (MR-proADM), midregional proatrial natriuretic peptide (MR-proANP), N-terminal pro-B-type natriuretic peptide (NT pro-BNP), copeptin, and cystatin C. After exclusion of those with prevalent CAS, subjects were thereafter followed in national patient registers for 23.4 (interquartile range 19.5-24.3) years regarding incident symptomatic and asymptomatic CAS. Results: Among 110 patients with confirmed incident CAS, 56 were symptomatic and 54 were asymptomatic. When including conventional risk markers in a Cox regression analysis, NT pro-BNP (hazard ratio [HR] 1.59; 95% confidence interval [CI]: 1.20-2.11), MR-proADM (HR 1.40; CI: 1.13-1.73), cystatin C (HR 1.21; CI: 1.02-1.43), and CRP (HR 1.53; CI: 1.13-1.73) were independently associated with incident symptomatic CAS, whereas no plasma biomarker was associated with incident asymptomatic CAS. Conclusion: Plasma biomarkers NT pro-BNP, MR-proADM, cystatin C, and CRP were independently associated with incident symptomatic CAS, whereas no such association could be demonstrated with incident asymptomatic CAS. As these biomarkers indicate future development of clinically relevant atherosclerotic CAS, their potential utility in relation to intensified preventive measures and selection of potential candidates for carotid surgery should be further evaluated.
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9.
  • Fatemi, Shahab, et al. (författare)
  • Copeptin, B-type natriuretic peptide and cystatin C are associated with incident symptomatic PAD
  • 2019
  • Ingår i: Biomarkers. - 1354-750X. ; 24:6, s. 615-621
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: The aim of this study is to evaluate plasma biomarkers as predictors for peripheral arterial disease (PAD). Materials and methods: Prospective longitudinal cohort study of middle-aged individuals from the cardiovascular cohort of the Malmö Diet and Cancer study (MDCS) (n = 5550; 1991–94). Cystatin C, copeptin, N-terminal pro-B-type natriuretic peptide (N-BNP), midregional proatrial natriuretic peptide (MR-proANP), mid-regional proadrenomedullin (MR-proADM), and conventional risk factors were measured at baseline. The diagnosis of symptomatic PAD was validated in 97% of the cases. Results: Cumulative incidence of PAD during median follow up of 23.4 years was 4.4% (men 5.9%, women 3.3%). Adjusted for age, sex, smoking, body mass index, hypertension, diabetes mellitus and total cholesterol, copeptin (hazard ratio [HR] 1.46; 95% confidence interval [CI] 1.19–1.80), N-BNP (HR 1.28; 95% CI 1.11–1.48), and cystatin C (HR 1.19; 95% CI 1.10–1.29) were independently associated with incident PAD. Subjects with the three biomarkers copeptin, N-BNP, and cystatin C in the highest quartiles, ran a high risk of incident PAD (HR 3.29; 95% CI 1.76–6.17) compared to those with no biomarker in the highest quartile. Conclusion: Copeptin, N-BNP, and cystatin C were associated with incident symptomatic PAD, implying that these biomarkers are sensitive indicators of early subclinical PAD.Clinical significance First prospective longitudinal cohort study evaluating Cystatin C, copeptin, N-terminal pro-B-type natriuretic peptide (N-BNP), midregional proatrial natriuretic peptide (MR-proANP), and mid-regional proadrenomedullin (MR-proADM) as predictors for peripheral arterial disease (PAD). Copeptin, N-BNP, and Cystatin C where independently associated with incident symptomatic PAD after adjustment for conventional risk factors. Copeptin, N-BNP, and Cystatin C seem to be sensitive indicators of early subclinical PAD.
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10.
  • Fatemi, Shahab, et al. (författare)
  • Effects of protons deflected by lunar crustal magnetic fields on the global lunar plasma environment
  • 2014
  • Ingår i: Journal of Geophysical Research - Space Physics. - : John Wiley & Sons. - 2169-9380 .- 2169-9402. ; 119:8, s. 6095-6105
  • Tidskriftsartikel (refereegranskat)abstract
    • Solar wind plasma interaction with lunar crustal magnetic fields is different than that of magnetized bodies like the Earth. Lunar crustal fields are, for typical solar wind conditions, not strong enough to form a (bow)shock upstream but rather deflect and perturb plasma and fields. Here we study the global effects of protons reflected from lunar crustal magnetic fields on the lunar plasma environment when the Moon is in the unperturbed solar wind. We employ a three-dimensional hybrid model of plasma and an observed map of reflected protons from lunar magnetic anomalies over the lunar farside. We observe that magnetic fields and plasma upstream over the lunar crustal fields compress to nearly 120% and 160% of the solar wind, respectively. We find that these disturbances convect downstream in the vicinity of the lunar wake, while their relative magnitudes decrease. In addition, solar wind protons are disturbed and heated at compression regions and their velocity distribution changes from Maxwellian to a non-Maxwellian. Finally, we show that these features persists, independent of the details of the ion reflection by the magnetic fields.
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11.
  • Fatemi, Shahab, et al. (författare)
  • Hybrid Simulations of Solar Wind Proton Precipitation to the Surface of Mercury
  • 2020
  • Ingår i: Journal of Geophysical Research - Space Physics. - : American Geophysical Union (AGU). - 2169-9380 .- 2169-9402. ; 125:4
  • Tidskriftsartikel (refereegranskat)abstract
    • We examine the effects of the interplanetary magnetic field (IMF) orientation and solar wind dynamic pressure on the solar wind proton precipitation to the surface of Mercury using a hybrid-kinetic model. We use our model to explain observations of Mercury's neutral sodium exosphere and compare our results with MESSENGER observations. For the typical solar wind dynamic pressure at Mercury our model shows a high proton flux precipitates through the magnetospheric cusps to the high latitudes on both hemispheres on the dayside, centered near the noon meridian with  ∼11° latitudinal extent in the north and ∼21° latitudinal extent in the south, which is consistent with MESSENGER observations. We show that this two-peak pattern is controlled by the radial component (Bx) of the IMF and not the Bz. Our model suggests that the southward IMF and its associated magnetic reconnection do not play a major role in controlling plasma precipitation to the surface of Mercury through the cusps. We found that the total precipitation rate through both of the cusps remain constant and independent of the IMF orientation. We also show that the solar wind proton incidence rate to the entire surface of Mercury is higher when the IMF has a northward component and nearly half of the incidence flux impacts the low latitudes on the nightside. During extreme solar events (e.g., coronal mass ejections), our model suggests that over 70 nPa solar wind dynamic pressure is required for the entire surface of Mercury to be exposed to the solar wind plasma.
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12.
  • Fatemi, Shahab, et al. (författare)
  • Ion Dynamics at the Magnetopause of Ganymede
  • 2022
  • Ingår i: Journal of Geophysical Research - Space Physics. - : John Wiley & Sons. - 2169-9380 .- 2169-9402. ; 127:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We study the dynamics of the thermal O+ and H+ ions at Ganymede's magnetopause when Ganymede is inside and outside of the Jovian plasma sheet using a three-dimensional hybrid model of plasma (kinetic ions, fluid electrons). We present the global structure of the electric fields and power density (E ⋅ J) in the magnetosphere of Ganymede and show that the power density at the magnetopause is mainly positive and on average is +0.95 and +0.75 nW/m3 when Ganymede is inside and outside the Jovian plasma sheet, respectively, but locally it reaches over +20 nW/m3. Our kinetic simulations show that ion velocity distributions at the vicinity of the upstream magnetopause of Ganymede are highly non-Maxwellian. We investigate the energization of the ions interacting with the magnetopause and find that the energy of those particles on average increases by a factor of 8 and 30 for the O+ and H+ ions, respectively. The energy of these ions is mostly within 1–100 keV for both species after interaction with the magnetopause, but a few percentages reach to 0.1–1 MeV. Our kinetic simulations show that a small fraction ((Formula presented.) 25%) of the corotating Jovian plasma reach the magnetopause, but among those >50% cross the high-power density regions at the magnetopause and gain energy. Finally, we compare our simulation results with Galileo observations of Ganymede's magnetopause crossings (i.e., G8 and G28 flybys). There is an excellent agreement between our simulations and observations, particularly our simulations fully capture the size and structure of the magnetosphere.
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13.
  • Fatemi, Shahab (författare)
  • Kinetic Modeling of the Solar Wind Plasma Interaction with the Moon
  • 2014
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The main purpose of this research is to understand various aspects of the solar wind plasma interaction with the Earth's Moon by the means of kinetic computer simulations. The Moon is essentially a non-conducting object, that has a tenuous atmosphere and no global magnetic field. Then the solar wind plasma impacts the lunar surface, where it is absorbed or neutralized for the most part. On average about 10% of the solar wind protons reflect in charge form from lunar crustal magnetization and up to 20% reflect from the lunar surface as neutral atoms.First we consider the Moon to be a perfect plasma absorber and we study the global effects of the solar wind plasma interaction with the Moon using a three-dimensional self-consistent hybrid model. We show that due to the plasma absorption in the lunar dayside, a void region forms behind the Moon and a plasma wake forms downstream. Then we study different parameters that control the lunar wake, discuss various mechanisms that fill in the wake, and compare our simulations with observations. We also discuss the effects of lunar surface plasma absorption on the solar wind proton velocity space distribution at close distances to the Moon in the lunar wake. Moreover, we show that three current systems form in the wake that enhance the magnetic fields in the central wake, depress the fields in the surrounding areas, and confine the fields and plasma perturbations within a Mach cone. Finally we study the effects of protons reflected from lunar crustal magnetic fields on the global lunar plasma environment. We show that the reflected protons interact with the solar wind plasma, compress the fields and plasma upstream in the lunar dayside and downstream outside the Mach cone. The conclusion of this thesis work is that the solar wind plasma interaction with the Moon is dynamic and complex. This is, however, due to the kinetic nature of this interaction because of the scales of the interaction regions where the Magnetohydrodynamics (fluid) approach cannot address the detailed physics. This reveals the importance of kinetic modeling to understand this interaction. The results of this study will feed forward to human space exploration, kinetic theories of plasma interaction with airless bodies, and fundamental plasma physics processes.
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14.
  • Fatemi, Shahab, et al. (författare)
  • Lp-PLA 2 activity and mass and CRP are associated with incident symptomatic peripheral arterial disease
  • 2019
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Long follow up is needed in prospective cohort study evaluation of plasma biomarkers for incident peripheral arterial disease (PAD) Middle-aged PAD-free individuals from the cardiovascular cohort of the Malmö Diet and Cancer study (n = 5550; 1991–94) were followed prospectively for a median time of 23.4 years. The plasma biomarkers lipoprotein-associated phospholipase A2 (Lp-PLA 2 ) activity and mass, proneurotensin, and CRP, were studied in relation to incidence of PAD until December 31 st , 2016. The diagnosis of PAD could be validated and confirmed in 98%. Cox regression was used to calculate hazard ratios (HR) per 1 standard deviation increment of each respective log transformed plasma biomarker. Cumulative incidence of PAD was 4.4% (men 5.9%, women 3.3%). Adjusting for age, gender, smoking, body mass index, hypertension, diabetes mellitus, Lp-PLA 2 activity (HR 1.33; 95% CI 1.17–1.52), Lp-PLA 2 mass (HR 1.20; 95% CI 1.05–1.37) and CRP (HR 1.55; 95% CI 1.36–1.76) remained independently associated with incident PAD. The plasma biomarkers Lp-PLA 2 activity and mass, and CRP were markers of PAD risk, implying that they might be useful biomarkers for subclinical atherosclerosis and atherosclerotic disease.
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15.
  • Fatemi, Shahab (författare)
  • Modeling the Lunar plasma wake
  • 2011
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • This thesis discusses the solar wind interaction with the Moon and the formation of the lunar plasma wake from a kinetic perspective. The Moon is essentially a non-conducting body which has a tenuous atmosphere and no global magnetic fields. The solar wind plasma impacts directly the lunar day-side and is absorbed by the lunar surface. This creates a plasma void and forms a wake at the night side of the Moon.We study the properties and structure of the lunar wake for typical solar wind conditions using a three-dimensional hybrid plasma solver. Also, we study the solar wind proton velocity space distribution functions at close distances to the Moon in the lunar wake and investigate the effects of lunar surface plasma absorption and non-isothermal solar wind velocity space distribution functions on the solar wind protons there.Finally, we compare the simulation results with the observations and show that a hybrid model of plasma can explain the kinetic aspects of the lunar wake and we investigate the effects of the lunar surface plasma absorption and non-isothermal solar wind velocity distribution on the solar wind proton properties there.
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16.
  • Fatemi, Shahab, et al. (författare)
  • Pro B-type Natriuretic Peptide and Midregional Proadrenomedullin are Associated with Incident Carotid Stenosis During Long Term Follow-up
  • 2021
  • Ingår i: Journal of Stroke and Cerebrovascular Diseases. - : Elsevier BV. - 1052-3057. ; 30:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Plasma biomarkers may be useful to detect healthy individuals at increased risk for atherosclerotic manifestations, such as carotid artery stenosis. The aim of this longitudinal cohort study was to evaluate new biomarkers in relation to C-reactive protein and conventional risk factors for carotid artery stenosis during long term follow-up Methods: The following markers were measured in 5550 middle-aged subjects: C-reactive protein, lipoprotein-associated phospholipase A2, proneurotensin, midregional pro-adrenomedullin, midregional pro-atrial natriuretic peptide, N-terminal pro B-type natriuretic peptide, copeptin, and cystatin C. Subjects with prevalent carotid artery stenosis were excluded. Subjects were followed in national patient registers for 23.4 (interquartile range 19.5–24.3) years regarding incident carotid artery stenosis, both operated and non-operated. Results: When including conventional risk markers in Cox regression, N-terminal pro B-type natriuretic peptide (Hazard ratio 1.36; 95% confidence interval 1.12–1.65; p = 0.002) was independently associated with incident carotid artery stenosis, whereas there were trends for C-reactive protein (HR 1.20; 95% confidence interval 0.98–1.48; p = 0.071), and midregional pro-adrenomedullin (Hazard ratio 1.21; 95% confidence interval 0.99–1.47; p = 0.061). Midregional pro-adrenomedullin (Hazard ratio 1.30; 95% confidence interval 1.03–1.65; p = 0.029) was independently associated with incident surgery for carotid artery stenosis, whereas there was a trend for N-terminal pro B-type natriuretic peptide (Hazard ratio 1.31; 95% confidence interval 1.00–1.72; p = 0.052). Conclusions: N-terminal pro B-type natriuretic peptide and midregional pro-adrenomedullin can be used as predictors for clinically detected carotid artery stenosis during long-term follow-up of healthy subjects.
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17.
  • Fatemi, Shahab, et al. (författare)
  • Solar wind plasma interaction with Gerasimovich lunar magnetic anomaly
  • 2015
  • Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 120:6, s. 4719-4735
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the results of the first local hybrid simulations (particle ions and fluid electrons) for the solar wind plasma interaction with realistic lunar crustal fields. We use a three-dimensional hybrid model of plasma and an empirical model of the Gerasimovich magnetic anomaly based on Lunar Prospector observations. We examine the effects of low and high solar wind dynamic pressures on this interaction when the Gerasimovich magnetic anomaly is located at nearly 20 degrees solar zenith angle. We find that for low solar wind dynamic pressure, the crustal fields mostly deflect the solar wind plasma, form a plasma void at very close distances to the Moon (below 20km above the surface), and reflect nearly 5% of the solar wind in charged form. In contrast, during high solar wind dynamic pressure, the crustal fields are more compressed, the solar wind is less deflected, and the lunar surface is less shielded from impinging solar wind flux, but the solar wind ion reflection is more locally intensified (up to 25%) compared to low dynamic pressures. The difference is associated with an electrostatic potential that forms over the Gerasimovich magnetic anomaly as well as the effects of solar wind plasma on the crustal fields during low and high dynamic pressures. Finally, we show that an antimoonward Hall electric field is the dominant electric field for similar to 3km altitude and higher, and an ambipolar electric field has a noticeable contribution to the electric field at close distances (<3km) to the Moon.
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18.
  • Fatemi, Shahab, et al. (författare)
  • The effects of lunar surface plasma absorption and solar wind temperature anisotropies on the solar wind proton velocity space distributions in the low-altitude lunar plasma wake
  • 2012
  • Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 117:10
  • Tidskriftsartikel (refereegranskat)abstract
    • We study the solar wind proton velocity space distribution functions on the lunar nightside at low altitudes (∼100 km) above the lunar surface using a three-dimensional hybrid plasma solver, when the Moon is in the unperturbed solar wind. When the solar wind encounters a passive obstacle, such as the Moon, without any strong magnetic field and no atmosphere, solar wind protons that impact the obstacle's surface are absorbed and removed from the velocity space distribution functions. We show first that a hybrid model of plasma is applicable to study the low-altitude lunar plasma wake by comparing the simulation results with observations. Then we examine the effects of a solar wind bi-Maxwellian velocity space distribution function and the lunar surface plasma absorption on the solar wind protons' velocity space distribution functions and their entry in the direction parallel to the interplanetary magnetic field lines into the low-altitude lunar wake. We present a backward Liouville method for particle-in-cell solvers that improves velocity space resolution. The results show that the lunar surface plasma absorption and anisotropic solar wind velocity space distributions result in substantial changes in the solar wind proton distribution functions in the low-altitude lunar plasma wake, modifying proton number density, velocity, and temperature there. Additionally, a large temperature anisotropy is found at close distances to the Moon on the lunar nightside as a consequence of the lunar surface plasma absorption effect
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19.
  • Fatemi, Shahab, et al. (författare)
  • The lunar wake current systems
  • 2013
  • Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 40:1, s. 17-21
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the lunar wake current systems when the Moon is assumed to be a non-conductive body, absorbing the solar wind plasma. We show that in the transition regions between the plasma void, the expanding rarefaction region, and the interplanetary plasma, there are three main currents flowing around these regions in the lunar wake. The generated currents induce magnetic fields within these regions and perturb the field lines there. We use a three-dimensional, self-consistent hybrid model of plasma (particle ions and fluid electrons) to show the flow of these three currents. First, we identify the different plasma regions, separated by the currents, and then we show how the currents depend on the interplanetary magnetic field direction. Finally, we discuss the current closures in the lunar wake.
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20.
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21.
  • Gunell, Herbert, et al. (författare)
  • Impact of radial interplanetary magnetic fields on the inner coma of comet 67P/Churyumov-Gerasimenko : Hybrid simulations of the plasma environment
  • 2024
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 682
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. The direction of the interplanetary magnetic field determines the nature of the interaction between a Solar System object and the solar wind. For comets, it affects the formation of both a bow shock and other plasma boundaries, as well as mass-loading. Around the nucleus of a comet, there is a diamagnetic cavity, where the magnetic field is negligible. Observations by the Rosetta spacecraft have shown that, most of the time, the diamagnetic cavity is located within a solar-wind ion cavity, which is devoid of solar wind ions. However, solar wind ions have been observed inside the diamagnetic cavity on several occasions. Understanding what determines whether or not the solar wind can reach the diamagnetic cavity also advances our understanding of cometsolar wind interaction in general.Aims. We aim to determine the influence of an interplanetary magnetic field directed radially out from the Sun that is, parallel to the solar wind velocity on the cometsolar wind interaction. In particular, we explore the possibility of solar wind protons entering the diamagnetic cavity under radial field conditions.Methods. We performed global hybrid simulations of comet 67P/Churyumov-Gerasimenko using the simulation code Amitis for two different interplanetary magnetic field configurations and compared the results to observations made by the Rosetta spacecraft.Results. We find that, when the magnetic field is parallel to the solar wind velocity, no bow shock forms and the solar wind ions are able to enter the diamagnetic cavity. A solar wind ion wake still forms further downstream in this case.Conclusions. The solar wind can enter the diamagnetic cavity if the interplanetary magnetic field is directed radially from the Sun, and this is in agreement with observations made by instruments on board the Rosetta spacecraft.
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22.
  • Holmström, Mats, et al. (författare)
  • The interaction between the Moon and the solar wind
  • 2012
  • Ingår i: Earth Planets and Space. - : Springer Science and Business Media LLC. - 1343-8832 .- 1880-5981. ; 64:2, s. 237-245
  • Tidskriftsartikel (refereegranskat)abstract
    • We study the interaction between the Moon and the solar wind using a three-dimensional hybrid plasma solver. The proton fluxes and electromagnetical fields are presented for typical solar wind conditions with different magnetic field directions. We find two different wake structures for an interplanetary magnetic field that is perpendicular to the solar wind flow, and for one that is parallell to the flow. The wake for intermediate magnetic field directions will be a mix of these two extreme conditions. Several features are consistent with a fluid interaction, e.g., the presence of a rarefaction cone, and an increased magnetic field in the wake. There are however several kinetic features of the interaction. We find kinks in the magnetic field at the wake boundary. There are also density and magnetic field variations in the far wake, maybe from an ion beam instability related to the wake refill. The results are compared to observations by the WIND spacecraft during a wake crossing. The model magnetic field and ion velocities are in agreement with the measurements. The density and the electron temperature in the central wake are not as well captured by the model, probably from the lack of electron physics in the hybrid model.
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23.
  • Khurana, Krishan K., et al. (författare)
  • The role of plasma slowdown in the generation of Rhea's Alfvén wings
  • 2017
  • Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 122:2, s. 1778-1788
  • Tidskriftsartikel (refereegranskat)abstract
    • Alfvén wings are known to form when a conducting or mass-loading object slows down a flowing plasma in its vicinity. Alfvén wings are not expected to be generated when an inert moon such as Rhea interacts with Saturn's magnetosphere, where the plasma impacting the moon is absorbed and the magnetic flux passes unimpeded through the moon. However, in two close polar passes of Rhea, Cassini clearly observed magnetic field signatures consistent with Alfvén wings. In addition, observations from a high-inclination flyby (Distance > 100 R Rh ) of Rhea on 3 June 2010 showed that the Alfvén wings continue to propagate away from Rhea even at this large distance. We have performed three-dimensional hybrid simulations of Rhea's interaction with Saturn's magnetosphere which show that the wake refilling process generates a plasma density gradient directed in the direction of corotating plasma. The resulting plasma pressure gradient exerts a force directed toward Rhea and slows down the plasma streaming into the wake along field lines. As on the same field lines, outside of the wake, the plasma continues to move close to its full speed, this differential motion of plasma bends the magnetic flux tubes, generating Alfvén wings in the wake. The current system excited by the Alfvén wings transfers momentum to the wake plasma extracting it from plasma outside the wake. Our work demonstrates that Alfvén wings can be excited even when a moon does not possess a conducting exosphere.
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24.
  • Kulezic, Andrea, et al. (författare)
  • Healthy diet and fiber intake are associated with decreased risk of incident symptomatic peripheral artery disease – A prospective cohort study
  • 2019
  • Ingår i: Vascular Medicine (United Kingdom). - 1358-863X. ; 24:6, s. 511-518
  • Tidskriftsartikel (refereegranskat)abstract
    • Peripheral artery disease (PAD) is caused by atherosclerosis and associated with an increased risk of leg amputation, cardiovascular disease, and death. A healthy diet has been shown to reduce the risk of cardiovascular events, but relationships between diet, fiber intake, and incidence of PAD are virtually unknown. The aim was to investigate the long-term impact of diet on the development of PAD among 26,010 middle-aged individuals in the prospective Malmö Diet and Cancer study (MDCS). Data on dietary intake were collected through a 7-day food diary combined with a food questionnaire and a 1-hour interview. Adherence to a recommended intake of six dietary components – saturated fat, polyunsaturated fat, fish and shellfish, fiber, fruit and vegetables, and sucrose – was scored (sum 0–6 points) to assess a diet quality index, adjusting for potential confounders. Cox regression analysis was used to estimate associations between diet variables and PAD incidence expressed in hazard ratios (HR) with 95% CI. During a median follow-up of 21.7 years, 1122 participants developed PAD. Diet score was associated with a reduced risk of PAD in multivariable analysis (p = 0.03). When mutually adjusting for all dietary variables, only adherence to recommended levels of fiber intake was associated with a reduced risk of incident PAD (HR 0.84; 95% CI 0.72–0.99). In this prospective, population-based study including 26,010 participants with over 20 years of follow-up, a healthy diet, especially a high intake of fiber, was associated with a reduced risk of PAD. Primary prevention programs directed against PAD should therefore include a fiber recommendation.
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25.
  • Lindkvist, Jesper, et al. (författare)
  • Callisto plasma interactions : Hybrid modeling including induction by a subsurface ocean
  • 2015
  • Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 120:6, s. 4877-4889
  • Tidskriftsartikel (refereegranskat)abstract
    • By using a hybrid plasma solver (ions as particles and electrons as a fluid), we have modeled the interaction between Callisto and Jupiter's magnetosphere for variable ambient plasma parameters. We compared the results with the magnetometer data from flybys (C3, C9, and C10) by the Galileo spacecraft. Modeling the interaction between Callisto and Jupiter's magnetosphere is important to establish the origin of the magnetic field perturbations observed by Galileo and thought to be related to a subsurface ocean. Using typical upstream magnetospheric plasma parameters and a magnetic dipole corresponding to the inductive response inside the moon, we show that the model results agree well with observations for the C3 and C9 flybys, but agrees poorly with the C10 flyby close to Callisto. The study does support the existence of a subsurface ocean at Callisto.
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