SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Evans P. A.) "

Sökning: WFRF:(Evans P. A.)

  • Resultat 1591-1600 av 1720
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1591.
  • Graham, Daniel B., et al. (författare)
  • Kinetic electrostatic waves and their association with current structures in the solar wind
  • 2021
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 656
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. A variety of kinetic electrostatic and electromagnetic waves develop in the solar wind and the relationship between these waves and larger scale structures, such as current sheets and ongoing turbulence, remain a topic of investigation. Similarly, the instabilities producing ion-acoustic waves in the solar wind are still an open question. Aims. The goals of this paper are to investigate electrostatic Langmuir and ion-acoustic waves in the solar wind at 0.5 AU and determine whether current sheets and associated streaming instabilities can produce the observed waves. The relationship between these waves and currents observed in the solar wind is investigated statistically. Methods. Solar Orbiter's Radio and Plasma Waves instrument suite provides high-resolution snapshots of the fluctuating electric field. The Low Frequency Receiver resolves the waveforms of ion-acoustic waves and the Time Domain Sampler resolves the waveforms of both ion-acoustic and Langmuir waves. Using these waveform data, we determine when these waves are observed in relation to current structures in the solar wind, estimated from the background magnetic field. Results. Langmuir and ion-acoustic waves are frequently observed in the solar wind. Ion-acoustic waves are observed about 1% of the time at 0.5 AU. The waves are more likely to be observed in regions of enhanced currents. However, the waves typically do not occur at current structures themselves. The observed currents in the solar wind are too small to drive instability by the relative drift between single ion and electron populations. When multi-component ion or electron distributions are present, the observed currents may be sufficient for instabilities to occur. Ion beams are the most plausible source of ion-acoustic waves in the solar wind. The spacecraft potential is confirmed to be a reliable probe of the background electron density when comparing the peak frequencies of Langmuir waves with the plasma frequency calculated from the spacecraft potential.
  •  
1592.
  •  
1593.
  •  
1594.
  • Hägg, Sara, et al. (författare)
  • Adiposity as a cause of cardiovascular disease : a Mendelian randomization study
  • 2015
  • Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 44:2, s. 578-586
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Adiposity, as indicated by body mass index (BMI), has been associated with risk of cardiovascular diseases in epidemiological studies. We aimed to investigate if these associations are causal, using Mendelian randomization (MR) methods. Methods: The associations of BMI with cardiovascular outcomes [coronary heart disease (CHD), heart failure and ischaemic stroke], and associations of a genetic score (32 BMI single nucleotide polymorphisms) with BMI and cardiovascular outcomes were examined in up to 22 193 individuals with 3062 incident cardiovascular events from nine prospective follow-up studies within the ENGAGE consortium. We used random-effects meta-analysis in an MR framework to provide causal estimates of the effect of adiposity on cardiovascular outcomes. Results: There was a strong association between BMI and incident CHD (HR = 1.20 per SD-increase of BMI, 95% CI, 1.12-1.28, P = 1.9.10(-7)), heart failure (HR = 1.47, 95% CI, 1.35-1.60, P = 9.10(-19)) and ischaemic stroke (HR = 1.15, 95% CI, 1.06-1.24, P = 0.0008) in observational analyses. The genetic score was robustly associated with BMI (beta = 0.030 SD-increase of BMI per additional allele, 95% CI, 0.028-0.033, P = 3.10(-107)). Analyses indicated a causal effect of adiposity on development of heart failure (HR = 1.93 per SD-increase of BMI, 95% CI, 1.12-3.30, P = 0.017) and ischaemic stroke (HR = 1.83, 95% CI, 1.05-3.20, P = 0.034). Additional cross-sectional analyses using both ENGAGE and CARDIoGRAMplusC4D data showed a causal effect of adiposity on CHD. Conclusions: Using MR methods, we provide support for the hypothesis that adiposity causes CHD, heart failure and, previously not demonstrated, ischaemic stroke.
  •  
1595.
  •  
1596.
  •  
1597.
  •  
1598.
  • Khotyaintsev, Yu, V, et al. (författare)
  • Density fluctuations associated with turbulence and waves First observations by Solar Orbiter
  • 2021
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 656
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims. The aim of this work is to demonstrate that the probe-to-spacecraft potential measured by RPW on Solar Orbiter can be used to derive the plasma (electron) density measurement, which exhibits both a high temporal resolution and a high level of accuracy. To investigate the physical nature of the solar wind turbulence and waves, we analyze the density and magnetic field fluctuations around the proton cyclotron frequency observed by Solar Orbiter during the first perihelion encounter (similar to 0.5AU away from the Sun). Methods. We used the plasma density based on measurements of the probe-to-spacecraft potential in combination with magnetic field measurements by MAG to study the fields and density fluctuations in the solar wind. In particular, we used the polarization of the wave magnetic field, the phase between the compressible magnetic field and density fluctuations, and the compressibility ratio (the ratio of the normalized density fluctuations to the normalized compressible fluctuations of B) to characterize the observed waves and turbulence. Results. We find that the density fluctuations are 180 degrees out of phase (anticorrelated) with the compressible component of magnetic fluctuations for intervals of turbulence, whereas they are in phase for the circular-polarized waves. We analyze, in detail, two specific events with a simultaneous presence of left- and right-handed waves at di fferent frequencies. We compare the observed wave properties to a prediction of the three-fluid (electrons, protons, and alphas) model. We find a limit on the observed wavenumbers, 10(-6) < k < 7 > 10(-6) m(-1), which corresponds to a wavelength of 7 x 10(6) > lambda > 10(6) m. We conclude that it is most likely that both the leftand right-handed waves correspond to the low-wavenumber part (close to the cut-o ff at Omega(cHe++)) of the proton-band electromagnetic ion cyclotron (left-handed wave in the plasma frame confined to the frequency range Omega(cHe++) < omega < Omega(cp)) waves propagating in the outwards and inwards directions, respectively. The fact that both wave polarizations are observed at the same time and the identified wave mode has a low group velocity suggests that the double-banded events occur in the source regions of the waves.
  •  
1599.
  • Laureati, P, et al. (författare)
  • Initiation of sodium polystyrene sulphonate and the risk of gastrointestinal adverse events in advanced chronic kidney disease: a nationwide study
  • 2020
  • Ingår i: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. - : Oxford University Press (OUP). - 1460-2385. ; 35:9, s. 1518-1526
  • Tidskriftsartikel (refereegranskat)abstract
    • BackgroundDespite long-standing clinical use of sodium polystyrene sulphonate (SPS) for hyperkalaemia management in chronic kidney disease (CKD), its safety profile remains poorly investigated.MethodsWe undertook an observational analysis of nephrology-referred adults with incident CKD Stage 4+ in Sweden during 2006–16 and with no previous SPS use. We studied patterns of use and adverse events associated to SPS initiation during follow-up. Patterns of SPS use were defined by chronicity of treatment and by prescribed dose. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) associated with SPS initiation (time-varying exposure) for the risk of severe (intestinal ischaemia, thrombosis or ulceration/perforation) and minor (de novo dispensation of laxatives or anti-diarrheal drugs) gastrointestinal (GI) events.ResultsOf 19 530 SPS-naïve patients with CKD, 3690 initiated SPS during follow-up. A total of 59% took SPS chronically, with an average of three dispensations/year. The majority (85%) were prescribed lower dosages than specified on the product label. During follow-up, 202 severe and 1149 minor GI events were recorded. SPS initiation was associated with a higher incidence of severe adverse events [adjusted HR 1.25 95% CI 1.05–1.49)], particularly in those receiving per label doses [1.54 (1.09–2.17)] and mainly attributed to ulcers and perforations. SPS initiation was also associated with higher incidence of minor GI events [adjusted HR 1.11 (95% CI 1.03–1.19)], regardless of dose, and mainly accounted for by de novo dispensation of laxatives.ConclusionsInitiation of SPS in patients with advanced CKD is associated with a higher risk of severe GI complications as well as the initiation of GI-related medications, particularly when prescribed at per label doses.
  •  
1600.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1591-1600 av 1720
Typ av publikation
tidskriftsartikel (1516)
konferensbidrag (44)
forskningsöversikt (15)
bokkapitel (3)
rapport (1)
Typ av innehåll
refereegranskat (1634)
övrigt vetenskapligt/konstnärligt (68)
Författare/redaktör
Zhu, J. (821)
Evans, H. (791)
Zhou, B. (785)
Fox, H. (779)
Meyer, J. (779)
Snyder, S. (776)
visa fler...
Burdin, S. (775)
Cooke, M. (775)
Kupco, A. (775)
Quadt, A. (775)
Sawyer, L. (775)
Abbott, B. (774)
Brandt, A. (774)
Lokajicek, M. (774)
Pleier, M. -A. (774)
Qian, J. (774)
Stark, J. (774)
Borissov, G. (773)
Brock, R. (773)
Kehoe, R. (773)
Khanov, A. (773)
Watts, G. (773)
Fiedler, F. (772)
Schwienhorst, R. (772)
Shabalina, E. (772)
Strauss, M. (772)
Hohlfeld, M. (770)
Rizatdinova, F. (770)
Severini, H. (770)
Hubacek, Z. (769)
Simak, V. (769)
Tsybychev, D. (769)
Filthaut, F. (766)
Nunnemann, T. (766)
Liu, Y. (764)
Han, L. (760)
Skubic, P. (759)
Gutierrez, P. (758)
Zieminska, D. (758)
Grivaz, J. -F. (758)
Neal, H. A. (743)
Sanders, M. P. (739)
Schamberger, R. D. (734)
Denisov, S. P. (733)
White, A. (714)
Vokac, P. (713)
Chakraborty, D. (711)
Buescher, V. (693)
Haas, A. (685)
Schwanenberger, C. (684)
visa färre...
Lärosäte
Lunds universitet (774)
Uppsala universitet (689)
Karolinska Institutet (377)
Stockholms universitet (284)
Kungliga Tekniska Högskolan (252)
Chalmers tekniska högskola (80)
visa fler...
Göteborgs universitet (78)
Umeå universitet (56)
Luleå tekniska universitet (31)
Linköpings universitet (14)
Örebro universitet (8)
Linnéuniversitetet (7)
Sveriges Lantbruksuniversitet (6)
Jönköping University (5)
Mittuniversitetet (5)
Malmö universitet (3)
Högskolan Dalarna (3)
Handelshögskolan i Stockholm (2)
Naturhistoriska riksmuseet (2)
Högskolan Väst (1)
RISE (1)
Karlstads universitet (1)
Marie Cederschiöld högskola (1)
visa färre...
Språk
Engelska (1720)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (1017)
Medicin och hälsovetenskap (272)
Teknik (36)
Samhällsvetenskap (18)
Lantbruksvetenskap (3)
Humaniora (3)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy