Energetic (greater than tens of keV) magnetospheric particle escape into the magnetosheath occurs commonly, irrespective of conditions that engender reconnection and boundary-normal magnetic fields. ...A signature observed by the Magnetospheric Multiscale (MMS) mission, simultaneous monohemispheric streaming of multiple species (electrons, H+, Hen+), is reported here as unexpectedly common in the dayside, dusk quadrant of the magnetosheath even though that region is thought to be drift-shadowed from energetic electrons. This signature is sometimes part of a pitch angle distribution evolving from symmetric in the magnetosphere, to asymmetric approaching the magnetopause, to monohemispheric streaming in the magnetosheath. While monohemispheric streaming in the magnetosheath may be possible without a boundary-normal magnetic field, the additional pitch angle depletion, particularly of electrons, on the magnetospheric side requires one. Observations of this signature in the dayside dusk sector imply that the static picture of magnetospheric drift-shadowing is inappropriate for energetic particle dynamics in the outer magnetosphere.
Purpose
Iron deficiency anemia is common in people with inflammatory bowel disease (IBD), causing deterioration in quality of life, which can be reversed by treatment that increases iron stores and ...hemoglobin levels. The present
post hoc
analyses estimate health state utility values for patients with IBD after treatment with ferric derisomaltose or ferric carboxymaltose and evaluate the health domains driving the changes.
Methods
SF-36v2 responses were recorded at baseline and day 14, 35, 49, and 70 from 97 patients enrolled in the randomized, double-blind, PHOSPHARE-IBD trial (ClinicalTrials.gov ID: NCT03466983), in which patients with IBD across five European countries were randomly allocated to either ferric derisomaltose or ferric carboxymaltose. Changes in SF-36v2 scale scores and SF-6Dv2 health utility values were analyzed by mixed models.
Results
In both treatment arms, SF-6Dv2 utility values and all SF-36v2 scale scores, except Bodily Pain, improved significantly (
p
= < 0.0001). The improvement in SF-6Dv2 utility values showed no significant treatment group difference. The improvement in utility values was completely explained by improvement in Vitality scores. Vitality scores showed significantly larger improvement with ferric derisomaltose versus ferric carboxymaltose (
p
= 0.026). Patients with the smallest decrease in phosphate had significantly larger improvements in Vitality scores at each time point (
p
= < 0.05 for all comparisons) and overall (
p
= 0.0006).
Conclusions
Utility values improved significantly with intravenous iron treatment. Improvement in utility values was primarily driven by Vitality scores, which showed significantly greater improvement in the ferric derisomaltose arm. Smaller decreases in phosphate were associated with significantly higher Vitality scores, suggesting that quality of life improvement is attenuated by hypophosphatemia. The utility values can inform future cost-utility analysis.
Aim
This study was designed to determine whether ET‐1 derived from endothelial cells contributes to oxidative stress in the glomerulus of mice subjected to a high‐salt diet and/or hypoxia.
Methods
...C57BL6/J control mice or vascular endothelial cell ET‐1 knockout (VEET KO) mice were subjected to 3‐h exposure to hypoxia (8% O2) and/or 2 weeks of high‐salt diet (4% NaCl) prior to metabolic cage assessment of renal function and isolation of glomeruli for the determination of reactive oxygen species (ROS).
Results
In control mice, hypoxia significantly increased urinary protein excretion during the initial 24 h, but only in animals on a high‐salt diet. Hypoxia increased glomerular ET‐1 mRNA expression in control, but not in vascular endothelial cell ET‐1 knockout (VEET KO) mice. Under normoxic conditions, mice on a high‐salt diet had approx. 150% higher glomerular ET‐1 mRNA expression compared with a normal‐salt diet (P < 0.05). High‐salt diet administration significantly increased glomerular ROS production in flox control, but not in glomeruli isolated from VEET KO mice. In C57BL6/J mice, the ETA receptor‐selective antagonist, ABT‐627, significantly attenuated the increase in glomerular ROS production produced by high‐salt diet. In addition, chronic infusion of C57BL6/J mice with a subpressor dose of ET‐1 (osmotic pumps) significantly increased the levels of glomerular ROS that were prevented by ETA antagonist treatment.
Conclusion
These data suggest that both hypoxia and a high‐salt diet increase glomerular ROS production via endothelial‐derived ET‐1‐ETA receptor activation and provide a potential mechanism for ET‐1‐induced nephropathy.
We present multipoint observations of earthward moving dipolarization fronts and energetic particle injections from NASAs Magnetospheric Multiscale mission with a focus on electron acceleration. From ...a case study during a substorm on 02 August 2015, we find that electrons are only accelerated over a finite energy range, from a lower energy threshold at approx. 7-9 keV up to an upper energy cutoff in the hundreds of keV range. At energies lower than the threshold energy, electron fluxes decrease, potentially due to precipitation by strong parallel electrostatic wavefields or initial sources in the lobes. Electrons at energies higher than the threshold are accelerated cumulatively by a series of impulsive magnetic dipolarization events. This case demonstrates how the upper energy cutoff increases, in this case from approx. 130 keV to >500 keV, with each depolarization/injection during sustained activity. We also present a simple model accounting for these energy limits that reveals that electron energization is dominated by betatron acceleration.
We report on the observations of an electron vortex magnetic hole corresponding to a new type of coherent structure in the turbulent magnetosheath plasma using the Magnetospheric Multiscale mission ...data. The magnetic hole is characterized by a magnetic depression, a density peak, a total electron temperature increase (with a parallel temperature decrease but a perpendicular temperature increase), and strong currents carried by the electrons. The current has a dip in the core region and a peak in the outer region of the magnetic hole. The estimated size of the magnetic hole is about 0.23 i (∼30 e) in the quasi-circular cross-section perpendicular to its axis, where i and e are respectively the proton and electron gyroradius. There are no clear enhancements seen in high-energy electron fluxes. However, there is an enhancement in the perpendicular electron fluxes at 90° pitch angle inside the magnetic hole, implying that the electrons are trapped within it. The variations of the electron velocity components Vem and Ven suggest that an electron vortex is formed by trapping electrons inside the magnetic hole in the cross-section in the M-N plane. These observations demonstrate the existence of a new type of coherent structures behaving as an electron vortex magnetic hole in turbulent space plasmas as predicted by recent kinetic simulations.
Vertebrate species worldwide are currently facing significant declines in many populations. Although we have gained substantial knowledge about the direct threats that affect individual species, ...these threats only represent a fraction of the broader vertebrate threat profile, which is also shaped by species interactions. For example, threats faced by prey species can jeopardize the survival of their predators due to food resource scarcity. Yet, indirect threats arising from species interactions have received limited investigation thus far. In this study, we investigate the indirect consequences of anthropogenic threats on biodiversity in the context of European vertebrate food webs. We integrated data on trophic interactions among over 800 terrestrial vertebrates, along with their associated human‐induced threats. We quantified and mapped the vulnerability of various components of the food web, including species, interactions, and trophic groups to six major threats: pollution, agricultural intensification, climate change, direct exploitation, urbanization, and invasive alien species and diseases. Direct exploitation and agricultural intensification were two major threats for terrestrial vertebrate food webs: affecting 34% and 31% of species, respectively, they threaten 85% and 69% of interactions in Europe. By integrating network ecology with threat impact assessments, our study contributes to a better understanding of the magnitude of anthropogenic impacts on biodiversity.
While direct threats to species are well studied, indirect threats arising from species interactions are less documented, especially on a macroecological scale. In this study, we show the importance of considering interactions to understand threats to biodiversity. By analyzing the vulnerability of European vertebrate food webs to six major anthropogenic threats, we highlight the far‐reaching impact of pressures such as direct exploitation and agricultural intensification, shedding light on the broader consequences of human activities on biodiversity.
In this paper we use the full armament of the MMS (Magnetospheric Multiscale) spacecraft to study magnetic reconnection in the turbulent magnetosheath downstream of a quasi‐parallel bow shock. ...Contrarily to the magnetopause and magnetotail cases, only a few observations of reconnection in the magnetosheath have been reported. The case study in this paper presents, for the first time, both fluid‐scale and kinetic‐scale signatures of an ongoing reconnection in the turbulent magnetosheath. The spacecraft are crossing the reconnection inflow and outflow regions and the ion diffusion region (IDR). Inside the reconnection outflows D shape ion distributions are observed. Inside the IDR mixing of ion populations, crescent‐like velocity distributions and ion accelerations are observed. One of the spacecraft skims the outer region of the electron diffusion region, where parallel electric fields, energy dissipation/conversion, electron pressure tensor agyrotropy, electron temperature anisotropy, and electron accelerations are observed. Some of the difficulties of the observations of magnetic reconnection in turbulent plasma are also outlined.
Key Points
Magnetic reconnection is observed in the magnetosheath
Reconnection is observed in turbulent environment
Fluid and kinetic signatures of magnetic reconnection are observed for the first time in the magnetosheath
Protons (ionized hydrogen) in the solar wind frequently exhibit distinct temperatures (T p and T p) perpendicular and parallel to the plasma's background magnetic field. Numerous prior studies of the ...interplanetary solar wind have shown that, as proton beta (β p) increases, a narrower range of proton temperature anisotropy (Rp T p/T p) values is observed. Conventionally, this effect has been ascribed to the actions of kinetic microinstabilities. This study is the first to use data from the Magnetospheric Multiscale Mission to explore such β p-dependent limits on Rp in Earth's magnetosheath. The distribution of these data across the (β p, Rp)-plane reveals limits on both Rp > 1 and Rp < 1. Linear Vlasov theory is used to compute contours of constant growth rate for the ion-cyclotron, mirror, parallel-firehose, and oblique-firehose instabilities. These instability thresholds closely align with the contours of the data distribution, which is consistent with these instabilities acting to limit extremes of proton temperature anisotropy in the magnetosheath.
Collisionless space plasma turbulence can generate reconnecting thin current sheets as suggested by recent results of numerical magnetohydrodynamic simulations. The Magnetospheric Multiscale (MMS) ...mission provides the first serious opportunity to verify whether small ion-electron-scale reconnection, generated by turbulence, resembles the reconnection events frequently observed in the magnetotail or at the magnetopause. Here we investigate field and particle observations obtained by the MMS fleet in the turbulent terrestrial magnetosheath behind quasi-parallel bow shock geometry. We observe multiple small-scale current sheets during the event and present a detailed look of one of the detected structures. The emergence of thin current sheets can lead to electron scale structures. Within these structures, we see signatures of ion demagnetization, electron jets, electron heating, and agyrotropy suggesting that MMS spacecraft observe reconnection at these scales.
We present results derived from the first multi-chord stellar occultations by the transneptunian object (50000) Quaoar, observed on 2011 May 4 and 2012 February 17, and from a single-chord ...occultation observed on 2012 October 15. If the timing of the five chords obtained in 2011 were correct, then Quaoar would possess topographic features (crater or mountain) that would be too large for a body of this mass. An alternative model consists in applying time shifts to some chords to account for possible timing errors. Satisfactory elliptical fits to the chords are then possible, yielding an equivalent radius R sub(equiv) = 555+ or -2.5 km and geometric visual albedo p sub(v) = 0.109+ or -0.007. Assuming that Quaoar is a Maclaurin spheroid with an indeterminate polar aspect angle, we derive a true oblateness of member of = 0.087 super(+0.0268) sub(-0.0175), an equatorial radius of 569 super(+24) sub(-17)km, and a density of 1.99 + or - 0.46 g cm super(-3). The orientation of our preferred solution in the plane of the sky implies that Quaoar's satellite Weywot cannot have an equatorial orbit. Finally, we detect no global atmosphere around Quaoar, considering a pressure upper limit of about 20 nbar for a pure methane atmosphere.
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