Imaging Thermal He(+)in Geospace from the Lunar Surface

By mass, thermal plasma dominates near-earth space and strongly influences the transport of energy and mass into the earth's atmosphere. It is proposed to play an important role in modifying the strength of space weather storms by its presence in regions of magnetic reconnection in the dayside magnetopause and in the near to mid-magnetotail. Ionospheric-origin thermal plasma also represents the most significant potential loss of atmospheric mass from our planet over geological time. Knowledge of the loss of convected thermal plasma into the solar wind versus its recirculation across high latitudes and through the magnetospheric flanks into the magnetospheric tail will enable determination of the mass balance for this mass-dominant component of the Geospace system and of its influence on global magnetospheric processes that are critical to space weather prediction and hence to the impact of space processes on human technology in space and on Earth. Our proposed concept addresses this basic issue of Geospace dynamics by imaging thermal He(+) ions in extreme ultraviolet light with an instrument on the lunar surface. The concept is derived from the highly successful Extreme Ultraviolet imager (EUV) flown on the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft. From the lunar surface an advanced EUV imager is anticipated to have much higher sensitivity, lower background noise, and higher communication bandwidth back to Earth. From the near-magnetic equatorial location on the lunar surface, such an imager would be ideally located to follow thermal He(+) ions to high latitudes, into the magnetospheric flanks, and into the magnetotail

The Properties and Curiosities of Inner Magnetospheric Ions as Seen by DE 1/RIMS

No abstract availabl

The Scalable Plasma Ion Composition and Electron Density (SPICED) Model for Earth's Inner Magnetosphere

The plasma mass loading of the terrestrial equatorial inner magnetosphere is a key determinant of the characteristics and propagation of ULF waves. Electron number density is also an important factor for other types of waves such as chorus, hiss and EMIC waves. In this paper, we use Van Allen Probe data from September 2012 to February 2019 to create average models of electron densities and average ion mass in the plasmasphere and plasmatrough, near the Earth’s magnetic equator. These models are combined to provide an estimate of the most probable plasma mass density in the equatorial region. We then use machine learning to form a set of models which are parameterized by the SuperMAG ring current index (SMR) based on the design of the average models. The resulting set of models are capable of predicting the average ion mass, electron density and plasma mass density in the range 2 < L < 5.9 and over all MLT sectors during a range of conditions where -75 < SMR < + 27 nT

The Data and Fits for a New Global Core Plasma Model and the Oddities Revealed

No abstract availabl

Investigation of EMIC wave scattering as the cause for the BARREL 17 January 2013 relativistic electron precipitation event: A quantitative comparison of simulation with observations

Abstract Electromagnetic ion cyclotron (EMIC) waves were observed at multiple observatory locations for several hours on 17 January 2013. During the wave activity period, a duskside relativistic electron precipitation (REP) event was observed by one of the Balloon Array for Radiation belt Relativistic Electron Losses (BARREL) balloons and was magnetically mapped close to Geostationary Operational Environmental Satellite (GOES) 13. We simulate the relativistic electron pitch angle diffusion caused by gyroresonant interactions with EMIC waves using wave and particle data measured by multiple instruments on board GOES 13 and the Van Allen Probes. We show that the count rate, the energy distribution, and the time variation of the simulated precipitation all agree very well with the balloon observations, suggesting that EMIC wave scattering was likely the cause for the precipitation event. The event reported here is the first balloon REP event with closely conjugate EMIC wave observations, and our study employs the most detailed quantitative analysis on the link of EMIC waves with observed REP to date. Key PointsQuantitative analysis of the first balloon REP with closely conjugate EMIC wavesOur simulation suggests EMIC waves to be a viable cause for the REP eventThe adopted model is proved to be applicable to simulating the REP event

Temperature of the Plasmasphere from Van Allen Probes HOPE

We introduce two novel techniques for estimating temperatures of very low energy space plasmas using, primarily, in situ data from an electrostatic analyzer mounted on a charged and moving spacecraft. The techniques are used to estimate proton temperatures during intervals where the bulk of the ion plasma is well below the energy bandpass of the analyzer. Both techniques assume that the plasma may be described by a one-dimensional E→×B→ drifting Maxwellian and that the potential field and motion of the spacecraft may be accounted for in the simplest possible manner, i.e., by a linear shift of coordinates. The first technique involves the application of a constrained theoretical fit to a measured distribution function. The second technique involves the comparison of total and partial-energy number densities. Both techniques are applied to Van Allen Probes Helium, Oxygen, Proton, and Electron (HOPE) observations of the proton component of the plasmasphere during two orbits on 15 January 2013. We find that the temperatures calculated from these two order-of-magnitude-type techniques are in good agreement with typical ranges of the plasmaspheric temperature calculated using retarding potential analyzer-based measurements—generally between 0.2 and 2 eV (2000–20,000 K). We also find that the temperature is correlated with L shell and hot plasma density and is negatively correlated with the cold plasma density. We posit that the latter of these three relationships may be indicative of collisional or wave-driven heating of the plasmasphere in the ring current overlap region. We note that these techniques may be easily applied to similar data sets or used for a variety of purposes

Contingent Valuation and Social Choice

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. How can you measure the net benefits to society from actions that impact environmental resources? An economist&apos;s answer is to employ Hicksian consumer surplus, determining the equivalent variation in income that leaves each consumer indifferent to the action. When consumers are rational and consumer surplus can be measured reliably from market demand functions, this is a satisfactory basis for welfare calculation, subject to the customary caveats about distributional equity and consistency if compensation is not actually paid. When externalities, public goods, or informational asymmetries interfere with the determination of consumer surplus from market demand functions, one can try to set up a hypothetical market to elicit an individual&apos;s equivalent variation, or willingness-to-pay (WTP). This is called the contingent valuation method (CVM). The approach elicits stated preferences from a sample of consumers using either openended questions that ask directly for WTP, or referendum (closed-ended) questions that present a bid or a sequence of bids to the consumer, and ask for a yes or no vote on whether each bid exceeds the subject&apos;s WTP. A single referendum experiment presents only one bid; a double referendum experiment presents a second bid that is conditioned on the subject&apos;s response to the first bid, lower if the first response is no and higher if it is yes. Agricultural &amp; Applied Economics Association and Oxford University Press An extensive literature has investigated the use of CVM to value environmental goods, and in recent years has promoted it for evaluation of goods such as endangered species and wilderness areas whose value comes primarily from existence rather than active use.&apos; The typical CVM experiment in environmental economics asks about a single commodity, often with a fairly abbreviated or stylized description that assumes the consumer can draw upon prior knowledge. Typically, there is no training of the consumer to reduce inconsistent (e.g. In assessing CVM, there are three commonsense questions that can be asked: (a) Is the method psychometrically robust, in that results cannot be altered substantively by changes in survey format, questionnaire design, and instructions that should be inconsequential when behavior is driven by maximization of rational preferences? (b) Is the method statistically reliable, in that the distribution of WTP can be estimated with acceptable precision using practical sample sizes? Reliability is a particular issue if CV surveys produce extreme responses with some probability, perhaps due to strategic misrepresentation. (c) Is the method economically sensible, in that the individual preferences measured by CVM are consistent with the logical requirements of rationality (e.g., transitivity), and at least broadly consistent with sensible features of economic preferences (e.g., plausible budget shares and income elasticities)? CVM might fail to meet these criteria because respondents receive incomplete information on the consequences of the available choices, or are given inadequate incentives to be truthful and avoid strategic misrepresentation, or because the experimental design is not sufficiently rich to detect and compensate for systematic and random response errors. Beyond such technical problems, there could be a fundamental failure of CVM if consumers do not have stable, classical preferences for the class of commodities, so that the foundations of Hicksian welfare analysis break down. Intuitively, the further removed a class of commodities from market goods where the consumer has the experience of repeated choices and the discipline of market forces, the greater the possibility of both technical and fundamental failures. The broad sweep of evidence from market research, cognitive psychology, and experimental economics suggests that the existence value of natural resources, involving very complex commodities that are far outside consumers&apos; market experience, will be vulnerable to these failures (McFadden 1986). The following sections discuss, in turn, a series of statistical issues in analyzing WTP data, parametric methods for estimating mean WTP, an experiment that was designed to detect and quantify technical failures of CVM, and the results from the experiment. Using referendum questions complicates matters only slightly, since votes at a sufficiently broad and closely spaced range of bid levels can be used to estimate directly the distribution of WTP, and this in turn can be used to estimate the population mean. This claim is proved in McFadden (1994), which gives practical nonparametric estimators, and describes the restrictions necessary on referendum experimental design for these estimators to have good largesample properties. In overview, the result is that with truthful referendum data there are estimators whose mean square error is inversely proportional to sample size, provided the experimental design &quot;undersmooths&quot; by taking a relatively large number of bid levels, with relatively small samples at each bid.2 For example, when WTP is restricted a priori to a finite interval, one could distribute the bids evenly over this interval, with one respondent at each level. The common practice in CV referendum studies of taking a relatively small number of bid levels leads to estimators whose mean square errors decline more slowly with sample size. Statistical Issues in CV Data 2 When the support of the WTP distribution is not finite, additional restrictions on tail behavior are needed to assure the existence of mean WTP and the stated rate of convergence of nonparametric estimators

Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial

BACKGROUND AND OBJECTIVES: Primary mitochondrial myopathies (PMMs) encompass a group of genetic disorders that impair mitochondrial oxidative phosphorylation, adversely affecting physical function, exercise capacity, and quality of life (QoL). Current PMM standards of care address symptoms, with limited clinical impact, constituting a significant therapeutic unmet need. We present data from MMPOWER-3, a pivotal, phase-3, randomized, double-blind, placebo-controlled clinical trial that evaluated the efficacy and safety of elamipretide in participants with genetically confirmed PMM. METHODS: After screening, eligible participants were randomized 1:1 to receive either 24 weeks of elamipretide at a dose of 40 mg/d or placebo subcutaneously. Primary efficacy endpoints included change from baseline to week 24 on the distance walked on the 6-minute walk test (6MWT) and total fatigue on the Primary Mitochondrial Myopathy Symptom Assessment (PMMSA). Secondary endpoints included most bothersome symptom score on the PMMSA, NeuroQoL Fatigue Short-Form scores, and the patient global impression and clinician global impression of PMM symptoms. RESULTS: Participants (N = 218) were randomized (n = 109 elamipretide; n = 109 placebo). The m0ean age was 45.6 years (64% women; 94% White). Most of the participants (n = 162 [74%]) had mitochondrial DNA (mtDNA) alteration, with the remainder having nuclear DNA (nDNA) defects. At screening, the most frequent bothersome PMM symptom on the PMMSA was tiredness during activities (28.9%). At baseline, the mean distance walked on the 6MWT was 336.7 ± 81.2 meters, the mean score for total fatigue on the PMMSA was 10.6 ± 2.5, and the mean T score for the Neuro-QoL Fatigue Short-Form was 54.7 ± 7.5. The study did not meet its primary endpoints assessing changes in the 6MWT and PMMSA total fatigue score (TFS). Between the participants receiving elamipretide and those receiving placebo, the difference in the least squares mean (SE) from baseline to week 24 on distance walked on the 6MWT was -3.2 (95% CI -18.7 to 12.3; p = 0.69) meters, and on the PMMSA, the total fatigue score was -0.07 (95% CI -0.10 to 0.26; p = 0.37). Elamipretide treatment was well-tolerated with most adverse events being mild to moderate in severity. DISCUSSION: Subcutaneous elamipretide treatment did not improve outcomes in the 6MWT and PMMSA TFS in patients with PMM. However, this phase-3 study demonstrated that subcutaneous elamipretide is well-tolerated. TRIAL REGISTRATION INFORMATION: Trial registered with clinicaltrials.gov, Clinical Trials Identifier: NCT03323749; submitted on October 12, 2017; first patient enrolled October 9, 2017. CLINICALTRIALS: gov/ct2/show/NCT03323749?term = elamipretide&draw = 2&rank = 9. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that elamipretide does not improve the 6MWT or fatigue at 24 weeks compared with placebo in patients with primary mitochondrial myopathy