De Gustibus non est Taxandum: Heterogeneity in Preferences and Optimal Redistribution

The prominent but unproven intuition that preference heterogeneity reduces re-distribution in a standard optimal tax model is shown to hold under the plausible condition that the distribution of preferences for consumption relative to leisure rises, in terms of first-order stochastic dominance, with income. Given mainstream functional form assumptions on utility and the distributions of ability and preferences, a simple statistic for the effect of preference heterogeneity on marginal tax rates is derived. Numerical simulations and suggestive empirical evidence demonstrate the link between this potentially measurable statistic and the quantitative implications of preference heterogeneity for policy.

X- and gamma-ray observations of the 15 November 1991 Solar Flare

This work expands the current understanding of the 15 November 1991 Solar Flare. The flare was a well observed event in radio to gamma-rays and is the first flare to be extensively studied with the benefit of detailed soft and hard X-ray images. In this work, we add data from all four instruments on the Compton Gamma Ray Observatory. Using these data we determined that the accelerated electron spectrum above 170 keV is best fit with a power law with a spectral index of −4.6, while the accelerated proton spectrum above 0.6 MeV is fit with a power law of spectral index −4.5. From this we computed lower limits for the energy content of these particles of∼1023 ergs (electrons) and ∼1027 ergs (ions above 0.6 MeV). These particles do not have enough energy to produce the white-light emission observed from this event. We computed a time constant of 26+20−15 s for the 2.223 MeV neutron capture line, which is consistent at the 2σ level with the lowest values of ∼70 s found for other flares. The mechanism for this short capture time may be better understood after analyses of high energy EGRET data that show potential evidence for pion emission near ∼100 MeV

Prevention of bone mineral changes induced by bed rest: Modification by static compression simulating weight bearing, combined supplementation of oral calcium and phosphate, calcitonin injections, oscillating compression, the oral diophosphonatedisodium etidronate, and lower body negative pressure

The phenomenon of calcium loss during bed rest was found to be analogous to the loss of bone material which occurs in the hypogravic environment of space flight. Ways of preventing this occurrence are investigated. A group of healthy adult males underwent 24-30 weeks of continuous bed rest. Some of them were given an exercise program designed to resemble normal ambulatory activity; another subgroup was fed supplemental potassium phosphate. The results from a 12-week period of treatment were compared with those untreated bed rest periods. The potassium phosphate supplements prevented the hypercalciuria of bed rest, but fecal calcium tended to increase. The exercise program did not diminish the negative calcium balance. Neither treatment affected the heavy loss of mineral from the calcaneus. Several additional studies are developed to examine the problem further

Polar cap patch segmentation of the tongue of ionization in the morning convection cell

Two types of poleward moving plasma concentration enhancements (PMPCEs) were observed during a sequence of pulsed reconnection events, both in the morning convection cell: Type L (low density) was associated with a cusp flow channel and seems likely to have been produced by ionization associated with particle precipitation, while Type H (high density) appeared to originate from the segmentation of the tongue of ionization by the processes which produced the Type L events. As a result, the Type L and Type H PMPCEs were interspersed, producing a complex density structure which underlines the importance of cusp flow channels as a mechanism for segmenting and structuring electron density in the cusp and shows the necessity of differentiating between at least two classes of electron density patches

A comparison between ion characteristics observed by the POLAR and DMSP spacecraft in the high-latitude magnetosphere

We study here the injection and transport of ions in the convection-dominated region of the Earth’s magnetosphere. The total ion counts from the CAMMICE MICS instrument aboard the POLAR spacecraft are used to generate occurrence probability distributions of magnetospheric ion populations. MICS ion spectra are characterised by both the peak in the differential energy flux, and the average energy of ions striking the detector. The former permits a comparison with the Stubbs et al. (2001) survey of He2+ ions of solar wind origin within the magnetosphere. The latter can address the occurrences of various classifications of precipitating particle fluxes observed in the topside ionosphere by DMSP satellites (Newell and Meng, 1992). The peak energy occurrences are consistent with our earlier work, including the dawn-dusk asymmetry with enhanced occurrences on the dawn flank at low energies, switching to the dusk flank at higher energies. The differences in the ion energies observed in these two studies can be explained by drift orbit effects and acceleration processes at the magnetopause, and in the tail current sheet. Near noon at average ion energies of _1 keV, the cusp and open LLBL occur further poleward here than in the Newell and Meng survey, probably due to convectionrelated time-of-flight effects. An important new result is that the pre-noon bias previously observed in the LLBL is most likely due to the component of this population on closed field lines, formed largely by low energy ions drifting earthward from the tail. There is no evidence here of mass and momentum transfer from the solar wind to the LLBL by nonreconnection coupling. At higher energies (_2–20 keV), we observe ions mapping to the auroral oval and can distinguish between the boundary and central plasma sheets. We show that ions at these energies relate to a transition from dawnward to duskward dominated flow, this is evidence of how ion drift orbits in the tail influence the location and behaviour of the plasma populations in the magnetosphere

Neutron and gamma‐ray measurements of the solar flare of 1991 June 9

The COMPTEL Imaging Compton Telescope on‐board the Compton Gamma Ray Observatory measured significant neutron and γ‐ray fluxes from the solar flare of 9 June 1991. The γ‐ray flux had an integrated intensity (≳1 MeV) of ∼30 cm−2, extending in time from 0136 UT to 0143 UT, while the time of energetic neutron emission extended approximately 10 minutes longer, indicating either extended proton acceleration to high energies or trapping and precipitation of energetic protons. The production of neutrons without accompanying γ‐rays in the proper proportion indicates a significant hardening of the precipitating proton spectrum through either the trapping or extended acceleration process

COMPTEL gamma ray and neutron measurements of solar flares

COMPTEL on the Compton Gamma Ray Observatory has measured the flux of x‐rays and neutrons from several solar flares. These data have also been used to image the Sun in both forms of radiation. Unusually intense flares occurred during June 1991 yielding data sets that offer some new insight into of how energetic protons and electrons are accelerated and behave in the solar environment. We summarize here some of the essential features in the solar flare data as obtained by COMPTEL during June 1991

Polar cap hot patches: enhanced density structures different from the classical patches in the ionosphere

Based on in situ and ground-based observations, a new type of “polar cap hot patch” has been identified that is different from the classical polar cap enhanced density structure (cold patches). Comparing with the classical polar cap patches, which are transported from the dayside sunlit region with dense and cold plasma, the polar cap hot patches are associated with particle precipitations (therefore field-aligned currents), ion upflows, and flow shears. The hot patches may have the same order of density enhancement as classical patches in the topside ionosphere, suggesting that the hot patches may be produced by transported photoionization plasma into flow channels. Within the flow channels, the hot patches have low-energy particle precipitation and/or ion upflows associated with field-aligned currents and flow shears. Corresponding Global Navigation Satellite System (GNSS) signal scintillation measurements indicate that hot patches may produce slightly stronger radio signal scintillation in the polar cap region than classical patches. A new type of polar cap patches, “polar cap hot patches,” is identified to differentiate enhanced density structures from classical patches. Hot patches are associated with particle precipitations, ion upflows, field-aligned currents, and shear flows in the polar cap. Hot patches may lead to slightly stronger ionospheric scintillations of GNSS signals in the polar cap region than classical patches