| 1. |
- Telloni, Daniele, et al.
(författare)
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Evolution of Solar Wind Turbulence from 0.1 to 1 au during the First Parker Solar Probe-Solar Orbiter Radial Alignment
- 2021
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 912:2
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Tidskriftsartikel (refereegranskat)abstract
- The first radial alignment between Parker Solar Probe and Solar Orbiter spacecraft is used to investigate the evolution of solar wind turbulence in the inner heliosphere. Assuming ballistic propagation, two 1.5 hr intervals are tentatively identified as providing measurements of the same plasma parcels traveling from 0.1 to 1 au. Using magnetic field measurements from both spacecraft, the properties of turbulence in the two intervals are assessed. Magnetic spectral density, flatness, and high-order moment scaling laws are calculated. The Hilbert-Huang transform is additionally used to mitigate short sample and poor stationarity effects. Results show that the plasma evolves from a highly Alfvenic, less-developed turbulence state near the Sun, to fully developed and intermittent turbulence at 1 au. These observations provide strong evidence for the radial evolution of solar wind turbulence.
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| 2. |
- D'Amicis, Raffaella, et al.
(författare)
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Investigating Alfvenic Turbulence in Fast and Slow Solar Wind Streams
- 2022
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Ingår i: Universe. - : MDPI. - 2218-1997. ; 8:7
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Tidskriftsartikel (refereegranskat)abstract
- Solar wind turbulence dominated by large-amplitude Alfvenic fluctuations, mainly propagating away from the Sun, is ubiquitous in high-speed solar wind streams. Recent observations performed in the inner heliosphere (from 1 AU down to tens of solar radii) have proved that also slow wind streams show sometimes strong Alfvenic signatures. Within this context, the present paper focuses on a comparative study on the characterization of Alfvenic turbulence in fast and slow solar wind intervals observed at 1 AU where degradation of Alfvenic correlations is expected. In particular, we compared the behavior of different parameters to characterize the Alfvenic content of the fluctuations, using also the Elsasser variables to derive the spectral behavior of the normalized cross-helicity and residual energy. This study confirms that the Alfvenic slow wind stream resembles, in many respects, a fast wind stream. The velocity-magnetic field (v-b) correlation coefficient is similar in the two cases as well as the amplitude of the fluctuations although it is not clear to what extent the condition of incompressibility holds. Moreover, the spectral analysis shows that fast wind and Alfvenic slow wind have similar normalized cross-helicity values but in general the fast wind streams are closer to energy equipartition. Despite the overall similarities between the two solar wind regimes, each stream shows also peculiar features, that could be linked to the intrinsic evolution history that each of them has experienced and that should be taken into account to investigate how and why Alfvenicity evolves in the inner heliosphere.
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| 3. |
- Di Castelnuovo, Augusto, et al.
(författare)
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NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) and the Risk of Stroke Results From the BiomarCaRE Consortium
- 2019
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Ingår i: Stroke. - : Lippincott Williams & Wilkins. - 0039-2499 .- 1524-4628. ; 50:3, s. 610-617
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: NT-proBNP (N-terminal pro-B-type natriuretic peptide) is a risk factor for atrial fibrillation and a marker of cardiac function used in the detection of heart failure. Given the link between cardiac dysfunction and stroke, NT-proBNP is a candidate marker of stroke risk. Our aim was to evaluate the association of NT-proBNP with stroke and to determine the predictive value beyond a panel of established risk factors. Methods: Based on the Biomarkers for Cardiovascular Risk Assessment in Europe-Consortium, we analyzed data of 58 173 participants (50% men; mean age 52 y) free of stroke from 6 community-based cohorts. NT-proBNP measurements were performed in the central Biomarkers for Cardiovascular Risk Assessment in Europe laboratory. The outcomes considered were total stroke and subtypes of stroke (ischemic/hemorrhagic). Results: During a median follow-up time of 7.9 years, we observed 1550 stroke events (1176 ischemic). Increasing quarters of the NT-proBNP distribution were associated with increasing risk of stroke (P for trend < 0.0001; multivariable Cox regression analysis adjusted for risk factors and cardiac diseases). Individuals in the highest NT-proBNP quarter (NTproBNP > 82.2 pg/mL) had 2-fold (95% CI, 75%-151%) greater risk of stroke than individuals in the lowest quarter (NTproBNP < 20.4 pg/mL). The association remained unchanged when adjusted for interim coronary events during followup, and though it was somewhat heterogeneous across cohorts, it was highly homogenous according to cardiovascular risk profile or subtypes of stroke. The addition of NT-proBNP to a reference model increased the C-index discrimination measure by 0.006 (P=0.0005), yielded a categorical net reclassification improvement of 2.0% in events and 1.4% in nonevents and an integrated discrimination improvement of 0.007. Conclusions: In European individuals free of stroke, levels of NT-proBNP are positively associated with risk of ischemic and hemorrhagic stroke, independently from several other risk factors and conditions. The addition of NT-proBNP to variables of established risk scores improves prediction of stroke, with a medium effect size.
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| 4. |
- Bruno, Roberto, et al.
(författare)
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Comparative Study of the Kinetic Properties of Proton and Alpha Beams in the Alfvénic Wind Observed by SWA-PAS On Board Solar Orbiter
- 2024
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 969:2
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Tidskriftsartikel (refereegranskat)abstract
- The problems of heating and acceleration of solar wind particles are of significant and enduring interest in astrophysics. The interactions between waves and particles are crucial in determining the distributions of proton and alpha particles, resulting in non-Maxwellian characteristics, including temperature anisotropies and particle beams. These processes can be better understood as long as the beam can be separated from the core for the two major components of the solar wind. We utilized an alternative numerical approach that leverages the clustering technique employed in machine learning to differentiate the primary populations within the velocity distribution rather than employing the conventional bi-Maxwellian fitting method. Separation of the core and beam revealed new features for protons and alphas. We estimated that the total temperature of the two beams was slightly higher than that of their respective cores, and the temperature anisotropy for the cores and beams was larger than 1. We concluded that the temperature ratio between alphas and protons largely over 4 is due to the presence of a massive alpha beam, which is approximately 50% of the alpha core. We provided evidence that the alpha core and beam populations are sensitive to Alfvénic fluctuations and the surfing effect found in the literature can be recovered only when considering the core and beam as a single population. Several similarities between proton and alpha beams would suggest a common and local generation mechanism not shared with the alpha core, which may not have necessarily been accelerated and heated locally.
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| 5. |
- Camen, Stephan, et al.
(författare)
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Cardiac Troponin I and Incident Stroke in European Cohorts : Insights From the BiomarCaRE Project
- 2020
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Ingår i: Stroke. - : Lippincott Williams & Wilkins. - 0039-2499 .- 1524-4628. ; 51:9, s. 2770-2777
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Stroke is a common cause of death and a leading cause of disability and morbidity. Stroke risk assessment remains a challenge, but circulating biomarkers may improve risk prediction. Controversial evidence is available on the predictive ability of troponin concentrations and the risk of stroke in the community. Furthermore, reports on the predictive value of troponin concentrations for different stroke subtypes are scarce.Methods: High-sensitivity cardiac troponin I (hsTnI) concentrations were assessed in 82 881 individuals (median age, 50.7 years; 49.7% men) free of stroke or myocardial infarction at baseline from 9 prospective European community cohorts. We used Cox proportional hazards regression to determine relative risks, followed by measures of discrimination and reclassification using 10-fold cross-validation to control for overoptimism. Follow-up was based upon linkage with national hospitalization registries and causes of death registries.Results: Over a median follow-up of 12.7 years, 3033 individuals were diagnosed with incident nonfatal or fatal stroke (n=1654 ischemic strokes, n=612 hemorrhagic strokes, and n=767 indeterminate strokes). In multivariable regression models, hsTnI concentrations were associated with overall stroke (hazard ratio per 1-SD increase, 1.15 [95% CI, 1.10-1.21]), ischemic stroke (hazard ratio, 1.14 [95% CI, 1.09-1.21]), and hemorrhagic stroke (hazard ratio, 1.10 [95% CI, 1.01-1.20]). Adding hsTnI concentrations to classical cardiovascular risk factors (C indices, 0.809, 0.840, and 0.736 for overall, ischemic, and hemorrhagic stroke, respectively) increased the C index significantly but modestly. In individuals with an intermediate 10-year risk (5%-20%), the net reclassification improvement for overall stroke was 0.038 (P=0.021).Conclusions: Elevated hsTnI concentrations are associated with an increased risk of incident stroke in the community, irrespective of stroke subtype. Adding hsTnI concentrations to classical risk factors only modestly improved estimation of 10-year risk of stroke in the overall cohort but might be of some value in individuals at an intermediate risk.
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| 6. |
- Di Castelnuovo, Augusto, et al.
(författare)
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Drinking alcohol in moderation is associated with lower rate of all-cause mortality in individuals with higher rather than lower educational level : findings from the MORGAM project
- 2023
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Ingår i: European Journal of Epidemiology. - : Springer Nature. - 0393-2990 .- 1573-7284. ; 38:8, s. 869-881
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Tidskriftsartikel (refereegranskat)abstract
- The association between socioeconomic status (SES) and alcohol-related diseases has been widely explored. Less is known, however, on whether the association of moderate drinking with all-cause mortality is modified by educational level (EL). Using harmonized data from 16 cohorts in the MORGAM Project (N = 142,066) the association of pattern of alcohol intake with hazard of all-cause mortality across EL (lower = primary-school; middle = secondary-school; higher = university/college degree) was assessed using multivariable Cox-regression and spline curves. A total of 16,695 deaths occurred in 11.8 years (median). In comparison with life-long abstainers, participants drinking 0.1–10 g/d of ethanol had 13% (HR = 0.87; 95%CI: 0.74–1.02), 11% (HR = 0.89; 0.84–0.95) and 5% (HR = 0.95; 0.89–1.02) lower rate of death in higher, middle and lower EL, respectively. Conversely, drinkers > 20 g/d had 1% (HR = 1.01; 0.82–1.25), 10% (HR = 1.10; 1.02–1.19) and 17% (HR = 1.17; 1.09–1.26) higher rate of death. The association of alcohol consumption with all-cause mortality was nonlinear, with a different J-shape by EL levels. It was consistent across both sexes and in various approaches of measuring alcohol consumption, including combining quantity and frequency and it was more evident when the beverage of preference was wine. We observed that drinking in moderation (≤ 10 g/d) is associated with lower mortality rate more evidently in individuals with higher EL than in people with lower EL, while heavy drinking is associated with higher mortality rate more evidently in individuals with lower EL than in people with higher EL, suggesting that advice on reducing alcohol intake should especially target individuals of low EL.
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