Exposure to fine particulate matter (PM2.5), an ambient air pollutant with mass-based standards promulgated under the Clean Air Act, and black carbon (BC), a common component of PM2.5, are both ...associated with cardiovascular health effects.
To elucidate whether BC is associated with distinct, or stronger, cardiovascular responses compared to PM2.5, we conducted a systematic review. We evaluated the associations of short- and long-term BC, or the related component elemental carbon (EC), with cardiovascular endpoints including heart rate variability, heart rhythm, blood pressure and vascular function, ST segment depression, repolarization abnormalities, atherosclerosis and heart function, in the context of what is already known about PM2.5.
We conducted a stepwise systematic literature search of the PubMed, Web of Science and TOXLINE databases and applied Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines for reporting our results.
Studies reporting effect estimates for the association of quantitative measurements of ambient BC (or EC) and PM2.5, with relevant cardiovascular endpoints (i.e. meeting inclusion criteria) were included in the review. Included studies were evaluated for risk of bias in study design and results.
Risk of bias evaluations assessed aspects of internal validity of study findings based on study design, conduct, and reporting to identify potential issues related to confounding or other biases. Study results are presented to facilitate comparison of the consistency of associations with PM2.5 and BC within and across studies.
Our results demonstrate similar associations for BC (or EC) and PM2.5 with the cardiovascular endpoints examined. Across studies, associations for BC and PM2.5 varied in their magnitude and precision, and confidence intervals were generally overlapping within studies. Where differences in the magnitude of the association between BC or EC and PM2.5 within a study could be discerned, no consistent pattern across the studies examined was apparent.
We were unable to assess the independence of the effect of BC, relative the effect of PM2.5, on the cardiovascular system, nor was information available to understand the impact of differential exposure misclassification.
Overall, the evidence indicates that both BC (or EC) and PM2.5 are associated with cardiovascular effects but the available evidence is not sufficient to distinguish the effect of BC (or EC) from that of PM2.5 mass.
•Similar associations of cardiovascular endpoints with black carbon (BC) and fine particulate matter (PM2.5) were observed.•Across studies, associations for BC and PM2.5 varied in their magnitude and precision.•Confidence intervals for the associations observed within studies were generally overlapping.•The evidence was not sufficient to determine if associations with BC were distinct, or stronger, than associations with PM2.5.
Research has shown that psychedelics, such as lysergic acid diethylamide (LSD), have profound anti-inflammatory properties mediated by 5-HT
2A
receptor signaling, supporting their evaluation as a ...therapeutic for neuroinflammation associated with neurodegenerative disease.
Objective
This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of orally repeated administration of 5 μg, 10 μg, and 20 μg LSD in older healthy individuals. In the current paper, we present safety, tolerability, pharmacokinetics, and pharmacodynamic measures that relate to safety, tolerability, and dose response.
Methods
This was a phase 1 double-blind, placebo-controlled, randomized study. Volunteers were randomly assigned to 1 of 4 dose groups (5 μg, 10 μg, 20 μg LSD, and placebo), and received their assigned dose on six occasions (i.e., every 4 days).
Results
Forty-eight older healthy volunteers (mean age = 62.9 years) received placebo (
n
= 12), 5 μg (
n
= 12), 10 μg (
n
= 12), or 20 μg (
n
= 12) LSD. LSD plasma levels were undetectable for the 5 μg group and peak blood plasma levels for the 10 μg and 20 μg groups occurred at 30 min. LSD was well tolerated, and the frequency of adverse events was no higher than for placebo. Assessments of cognition, balance, and proprioception revealed no impairment.
Conclusions
Our results suggest safety and tolerability of orally administered 5 μg, 10 μg, and 20 μg LSD every fourth day over a 21-day period and support further clinical development of LSD for the treatment and prevention of Alzheimer’s disease (AD).
The causes of age-related hyperkyphosis (HK) include osteoporosis, but only 1/3 of those most severely affected have vertebral fractures, suggesting that there are other important, and potentially ...modifiable causes. We hypothesized that muscle mass and quality may be important determinants of kyphosis in older persons.
We recruited 72 persons >65 years to participate in a prospective study designed to evaluate kyphosis and fall risk. At the baseline visit, participants had their body composition measures completed using Dual Energy X-ray Absorptiometry (DXA). They had kyphosis measured in either the standing S or lying L position: 1) Cobb angle from DXA L; 2) Debrunner kyphometer S; 3) architect's flexicurve ruler S; and 4) blocks method L. Multivariable linear/logistic regression analyses were done to assess the association between each body composition and 4 kyphosis measures.
Women (n = 52) were an average age of 76.8 (SD 6.7) and men 80.5 (SD 7.8) years. They reported overall good/excellent health (93%), the average body mass index was 25.3 (SD 4.6) and 35% reported a fall in the past year. Using published cut-offs, about 20-30% were determined to have HK. For the standing assessments of kyphosis only, after adjusting for age, sex, weight and hip BMD, persons with lower TLM were more likely to be hyperkyphotic.
Lower TLM is associated with HK in older persons. The results were stronger when standing measures of kyphosis were used, suggesting that the effects of muscle on thoracic kyphosis are best appreciated under spinal loading conditions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We present the first comparison of Jupiter's auroral morphology with an extended, continuous, and complete set of near‐Jupiter interplanetary data, revealing the response of Jupiter's auroras to the ...interplanetary conditions. We show that for ∼1–3 days following compression region onset, the planet's main emission brightened. A duskside poleward region also brightened during compressions, as well as during shallow rarefaction conditions at the start of the program. The power emitted from the noon active region did not exhibit dependence on any interplanetary parameter, though the morphology typically differed between rarefactions and compressions. The auroras equatorward of the main emission brightened over ∼10 days following an interval of increased volcanic activity on Io. These results show that the dependence of Jupiter's magnetosphere and auroras on the interplanetary conditions are more diverse than previously thought.
Plain Language Summary
Jupiter's auroras (northern lights) are the brightest in the solar system, over a hundred times brighter than the Earth's. Auroras on Earth are driven by the solar wind, a million mile‐per‐hour stream of charged particles flowing away from the Sun, hitting the Earth's magnetic field, and stirring it around, but it is not known whether the solar wind causes any significant auroras on Jupiter. The main reason for this uncertainty is a lack of observations of the planet's auroras obtained while spacecraft have been near Jupiter and able to supply a full and continuous set of measurements of the solar wind and its accompanying magnetic field. In early mid‐2016 Juno approached Jupiter, providing such an interplanetary data set, and we obtained over a month's worth of observations of Jupiter's auroras using the Hubble Space Telescope. We saw several solar wind storms, each causing auroral fireworks on Jupiter. We captured the most powerful auroras observed by Hubble to date, brightened main oval emissions, and flashing high‐latitude patches of auroras during the solar wind storms. These results indicate that Jupiter's auroral response to the solar wind is more diverse than we previously have thought.
Key Points
We present the first comparison of Jupiter's auroras with an extended and complete set of near‐Jupiter interplanetary data
During compressions, the well‐defined sector of Jupiter's emission and the dusk poleward region brightened, the latter pulsating
The power emitted from the noon active region did not exhibit dependence on any interplanetary parameter, though the morphology changed
We compare Hubble Space Telescope observations of Jupiter's FUV auroras with contemporaneous conjugate Juno in situ observations in the equatorial middle magnetosphere of Jupiter. We show that bright ...patches on and equatorward of the main emission are associated with hot plasma injections driven by ongoing active magnetospheric convection. During the interval that Juno crossed the magnetic field lines threading the complex of auroral patches, a series of energetic particle injection signatures were observed, and immediately prior, the plasma data exhibited flux tube interchange events indicating ongoing convection. This presents the first direct evidence that auroral morphology previously termed “strong injections” is indeed a manifestation of magnetospheric injections, and that this morphology indicates that Jupiter's magnetosphere is undergoing an interval of active iogenic plasma outflow.
Plain Language Summary
Auroras, known as the “Northern (or Southern) Lights” on Earth, are spectacular manifestations of energetic processes occurring in the space environment of a planet. The behavior of Jupiter's magnetosphere is dominated by the planet's rapid rotation, along with the centrifugally‐driven outflow of plasma (ionized gas) originating from active volcanoes on the moon Io. A prominent auroral feature on Jupiter has for many years been interpreted as a sign that Jupiter's magnetosphere is undergoing active convection, in which plasma from Io “falls” away from the planet, to be replaced by hot, relatively empty “bubbles” known as injections, moving inward. This feature comprises prominent patches of bright emission that are often observed in Jupiter's auroras, though the evidence associating them with injections has been largely circumstantial. Here we show that the NASA Juno spacecraft flew through such injections in the equatorial magnetosphere on magnetic field lines mapping to a cluster of auroral patches as observed by HST. The Juno data also indicated the interval was characterized by signatures of convection and outflow of plasma originating from Io. This demonstrates that auroral patches are signatures of injections, and that auroral emissions are an important tool for diagnosing the behavior of planetary magnetospheres.
Key Points
Bright FUV auroral patches on Jupiter are associated with magnetospheric injections and magnetospheric convection
Hubble Space Telescope and Juno equatorial data show a cluster of patches is magnetically conjugate with energetic particle injections
The interval also exhibits flux tube interchange and lagging magnetic field associated with plasma mass outflow
The Hubble Space Telescope (HST) data set obtained over two campaigns in 2007 is used to determine the long‐term variability of the different components of Jupiter's auroras. Three regions on the ...planet's disc are defined: the main oval, the low‐latitude auroras, and the high‐latitude auroras. The UV auroral power emitted from these regions is extracted and compared to estimated solar wind conditions projected to Jupiter's orbit from Earth. In the first campaign the emitted power originated mainly from the main oval and the high‐latitude regions, and in the second campaign the high‐latitude and main oval auroras were dimmer and less variable, while the low‐latitude region exhibited bright, patchy emission. We show that, apart from during specific enhancement events, the power emitted from the poleward auroras is generally uncorrelated with that of the main oval. The exception events are dawn storms and compression region enhancements. It is shown that the former events, typically associated with intense dawnside main oval auroras, also result in the brightening of the high‐latitude auroras. The latter events associated with compression regions exhibit a particular auroral morphology; that is, where it is narrow and well defined, the main oval is bright and located ∼1° poleward of its previous location, and elsewhere it is faint. Instead there is bright emission in the poleward region in the postnoon sector where distinct, bright, sometimes multiple arcs form.
We present the first large‐scale statistical survey of the Jovian main emission (ME) to map auroral properties from their ionospheric locations out into the equatorial plane of the magnetosphere, ...where they are compared directly to in‐situ spacecraft measurements. We use magnetosphere‐ionosphere (MI) coupling theory to calculate currents from the auroral brightness as measured with the Hubble Space Telescope and from plasma flow speeds measured in‐situ with the Galileo spacecraft. The effective Pedersen conductance of the ionosphere ΣP∗ $\left({{\Sigma }}_{P}^{\ast }\right)$ remains a free parameter in this comparison. We calculate the Pedersen conductance from the combined data sets, and find it ranges from 0.03<ΣP∗<2.40 $0.03< {{\Sigma }}_{P}^{\ast }< 2.40$ mho overall with averages of 0.13−0.07+0.26 $0.1{3}_{-0.07}^{+0.26}$ mho in the north and 0.16−0.10+0.34 $0.1{6}_{-0.10}^{+0.34}$ mho in the south. Considering the HST‐derived field‐aligned currents per radian of azimuth only, we find values of I‖=9.34−3.54+5.72 ${I}_{\Vert }=9.3{4}_{-3.54}^{+5.72}$ MA rad−1 and I‖=8.61−3.05+6.77 ${I}_{\Vert }=8.6{1}_{-3.05}^{+6.77}$ MA rad−1 in the north and south, respectively, in general agreement with previous results. Taking the currents and effective Pedersen conductance together, we find that the average ME intensity and plasma flow speed in the middle magnetosphere (10–30 RJ) are broadly consistent with one another under MI coupling theory. We find evidence for peaks in the distribution of ΣP∗ ${{\Sigma }}_{P}^{\ast }$ near dawn, then again near 12 and 14 hr magnetic local time (MLT). This variation in Pedersen conductance with MLT may indicate the importance of conductance in modulating MLT‐ and local‐time‐asymmetries in the ME, including the apparent subcorotation of some auroral features within the ME.
Plain Language Summary
The brightest part of Jupiter's aurorae– the main emission– forms arcs of sheet‐like lights surrounding both magnetic poles, similar to the Earth's aurorae. At both planets, these lights are caused by charged particles flowing into the planet's atmosphere, where they collide with gases and glow. According to one theory, at Jupiter these particles are electrons which flow in electrical currents connecting the planet to the charged‐particle‐filled space surrounding it. Here, we use Hubble Space Telescope images of Jupiter's aurorae spanning a decade to build up an average picture of the brightness and location of this main emission. The brightness is related to the energy of the electrons, which in turn is related to the strength of the electrical currents. We then use particle measurements made by the Galileo spacecraft in orbit around Jupiter to make an average picture of these particles as they move around Jupiter. These speeds are related to the same electrical currents, but include an electrical conductivity term describing how easily currents flow through Jupiter's auroral atmosphere. We combine all these measurements to calculate the conductivity, and present results which are consistent with expectations but which fluctuate more quickly than expected in parts of the main emission.
Key Points
The effective ionospheric Pedersen conductance in Jupiter's main emission auroral region is derived from remote and in‐situ measurements
Effective Pedersen conductances of ∼0.14 mho and field‐aligned auroral currents near ∼10 MA/rad−1 are derived, consistent with past work
The effective Pedersen conductance varies significantly in magnetic local time, and may explain the enigmatic motions of some auroral forms
While the terrestrial aurorae are known to be driven primarily by the interaction of the Earth's magnetosphere with the solar wind, there is considerable evidence that auroral emissions on Jupiter ...and Saturn are driven primarily by internal processes, with the main energy source being the planets' rapid rotation. Prior observations have suggested there might be some influence of the solar wind on Jupiter's aurorae and indicated that auroral storms on Saturn can occur at times of solar wind pressure increases. To investigate in detail the dependence of auroral processes on solar wind conditions, a large campaign of observations of these planets has been undertaken using the Hubble Space Telescope, in association with measurements from planetary spacecraft and solar wind conditions both propagated from 1 AU and measured near each planet. The data indicate a brightening of both the auroral emissions and Saturn kilometric radiation at Saturn close in time to the arrival of solar wind shocks and pressure increases, consistent with a direct physical relationship between Saturnian auroral processes and solar wind conditions. At Jupiter the correlation is less strong, with increases in total auroral power seen near the arrival of solar wind forward shocks but little increase observed near reverse shocks. In addition, auroral dawn storms have been observed when there was little change in solar wind conditions. The data are consistent with some solar wind influence on some Jovian auroral processes, while the auroral activity also varies independently of the solar wind. This extensive data set will serve to constrain theoretical models for the interaction of the solar wind with the magnetospheres of Jupiter and Saturn.
Earth-based detection of Uranus' aurorae Lamy, L.; Prangé, R.; Hansen, K. C. ...
Geophysical research letters,
April 2012, Letnik:
39, Številka:
7
Journal Article
Recenzirano
Odprti dostop
This study is based on multi‐planet multi‐wavelength observations of planetary aurorae throughout the heliosphere, acquired along the propagation path of a series of consecutive interplanetary ...shocks. The underlying motivation to track the shocks was to increase the probability of detection of auroral emissions at Uranus. Despite several Earth‐based attempts in the past few years, at Far‐UV (FUV) and Near‐IR (NIR) wavelengths, such emissions have never been unambiguously re‐observed since their discovery by Voyager 2 in 1986. Here, we present a campaign of FUV observations of Uranus obtained in November 2011 with the Hubble Space Telescope (HST) during active solar wind conditions. We positively identify auroral signatures in several of these HST measurements, together with some obtained in 1998, representing the first images of Uranus' aurorae. We analyze their characteristics and discuss the implications for the asymmetric Uranian magnetosphere and its highly variable interaction with the solar wind flow from near‐solstice (1986) to near‐equinox (2011) configurations.
Key Points
We report the first Earth‐based detections of Uranus aurorae
This enabled us to investigate the atypical Uranian magnetosphere
This opens a wide field of investigations of this poorly understood magnetosphere
Illuminating the Motions of Jupiter's Auroral Dawn Storms Rutala, M. J.; Clarke, J. T.; Mullins, J. D. ...
Journal of geophysical research. Space physics,
June 2022, 2022-06-00, 20220601, Letnik:
127, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Jupiter's auroral main emission (ME) has long been considered to be the result of currents keeping plasma corotating with the surrounding magnetosphere. As a result, the ME corotates with the planet, ...and individual auroral features making up the ME roughly follow suit. Jupiter's dawn storms, some of the rarest and brightest auroral features within the ME, are an exception, as they do not corotate but instead remain fixed near local dawn. The causes of this enigmatic motion are not fully understood. To test the significance of this motion, we have developed a process to identify auroral features and measure their degree of corotational motion, including dawn storms, in archival Hubble Space Telescope images of the Jovian ultraviolet aurorae. We compare motions of features inside and outside the dawn sector, characterizing the exact motions of dawn storms and providing context for these motions for the first time. In keeping with previous studies, we expected to identify features fixed near local dawn in 10% of observations; instead, we find that half of all features near local dawn lag corotation. We show that subcorotating dawn emissions are far more common than previously thought, and that the drivers of this motion must be similarly common. Corotational motion must be considered when identifying the processes driving all dawn aurorae, including the dawn storms. We explore the consistency of this result with various theories of dawn ME formation and propose that aspects of the known current system relating to the Sun‐Jupiter geometry can explain this behavior.
Plain Language Summary
Jupiter's aurorae vary widely in brightness, shape, and motion across the planet. The brightest part of these aurorae, the main emission, consists of two ovals of nearly permanent lights partially surrounding the northern and southern magnetic poles, superficially similar to the auroral ovals of the Earth. This portion of the aurorae is thought to be created by the interaction of Jupiter's powerful magnetic field, fast rotation rate, and plasma produced from material ejected by the volcanic moon Io. This system as a whole moves at about the same speed as Jupiter's rotation, so it is expected that the aurorae would also rotate at this speed, appearing fixed in Jupiter's atmosphere. Dawn storms– rare, bright aurorae that appear near local dawn– seem to conflict with this picture. These storms move slower than the planet rotates, appearing to remain fixed near dawn. Here, we measure the rotation rates of auroral features across Jupiter to understand how often dawn storms occur and how significant their motion is. We find that auroral features often move slower than Jupiter's rotation rate throughout the dawn sector, which is surprising considering the rarity of dawn storms and that most auroral features are expected to match Jupiter's rotation.
Key Points
A novel, fully automated method to identify and measure discrete auroral features in Jupiter's auroral main emission is described
Nearly five times more auroral forms are found to significantly lag behind rigid corotation in the dawn sector than expected
Jovian auroral theories must be expanded to better explain the enigmatic motions of dawn auroral features, which are too common to ignore
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