Representations of first order function types as terminal coalgebras

Cosmic rays provide an important source for free electrons in Earth's atmosphere and also in dense interstellar regions where they produce a prevailing background ionization. We utilize a Monte Carlo cosmic ray transport model for particle energies of 10(6) eV <E <10(9) eV, and an analytic cosmic ray transport model for particle energies of 10(9) eV <E <10(12) eV in order to investigate the cosmic ray enhancement of free electrons in substellar atmospheres of free-floating objects. The cosmic ray calculations are applied to Drift-Phoenix model atmospheres of an example brown dwarf with effective temperature T-eff = 1500 K, and two example giant gas planets (T-eff = 1000 K, 1500 K). For the model brown dwarf atmosphere, the electron fraction is enhanced significantly by cosmic rays when the pressure p(gas) <10(-2) bar. Our example giant gas planet atmosphere suggests that the cosmic ray enhancement extends to 10(-4)-10(-2) bar, depending on the effective temperature. For the model atmosphere of the example giant gas planet considered here (T-eff = 1000 K), cosmic rays bring the degree of ionization to f(e) greater than or similar to 10(-8) when p(gas) <10(-8) bar, suggesting that this part of the atmosphere may behave as a weakly ionized plasma. Although cosmic rays enhance the degree of ionization by over three orders of magnitude in the upper atmosphere, the effect is not likely to be significant enough for sustained coupling of the magnetic field to the gas.Publisher PDFPeer reviewe

Exploring the stigma of food stamps

This paper reports on theoretical research into the effect of stigma and social norms on policy outcomes of the Food Stamp program, in particular the effect on the caseload. As a general rule, it is impossible to predict whether norms will amplify or dampen the response of caseloads to any given policy intervention. Sometimes they have an effect, sometimes they do not. Much depends on whether the norms themselves change very much in response to policy changes. Social feedback (each norm violation encourages more violations) makes policy predictions uncertain. It can translate very small shocks into very large changes in the caseload. Norm systems can collapse abruptly. Norms can alleviate administrative problems involving targeting, since norms can define "true need" in a social sense and allow all of the truly needy to claim benefits. Eligible nonparticipants are viewed as "not needy" in the social sense, though they may be needy according to objective criteria. Norms may also lessen a program's incentive effects (against work, for example). Norms may exacerbate administrative problems involving resource availability. To the extent that program eligibility differs from socially defined need, the program will be unpopular. Norms also add considerable uncertainty to the environment of policy planning and execution. Policymakers who hope to reduce the influence of stigma on program resources and administration should consider localizing program eligibility rules, so that the rules correspond more closely to social definitions of need. Intense, broad-based local outreach efforts may also reduce stigma's power.

An investigation of the optimum design and flight of rockets

Variational methods for determining optimum design and flight of rocket

Under erasure: Jenny Holzer's war paintings

This article examines Jenny Holzer’s painterly reworkings of redacted American military documents, comparing her practice with some of Nancy Spero’s extended visual narratives of torture and victimization. As two artists immersed in a feminist visual politics (and poetics) of representation where language is both a vehicle and a form of expression, they adopt contrasting strategies of transformation: for Spero via allegory and the mythic, for Holzer through an aesthetic of negation. I read their work partly through Jacques Rancière’s notion of the necessity for bringing traumatic events into visibility, and I argue that in their respective scripto-visual artworks and sensitivity to the materiality of language and its performative dimension, they ‘make the inhuman perceptible’. I also consider their practice as evidence of an ongoing project of foregrounding arts responsibility as witness to history and the historical subject, seeing in their respective modes of figuration and emphasis upon surface (presence/absence, colour, writing) a means of inscribing the body in the text

Social attitudes modulate automatic imitation

In naturalistic interpersonal settings, mimicry or ‘automatic imitation’ generates liking, affiliation, cooperation and other positive social attitudes. The purpose of this study was to find out whether the relationship between social attitudes and mimicry is bidirectional: Do social attitudes have a direct and specific effect on mimicry? Participants were primed with pro-social, neutral or anti-social words in a scrambled sentence task. They were then tested for mimicry using a stimulus-response compatibility procedure. In this procedure, participants were required to perform a pre-specified movement (e.g. opening their hand) on presentation of a compatible (open) or incompatible (close) hand movement. Reaction time data were collected using electromyography (EMG) and the magnitude of the mimicry / automatic imitation effect was calculated by subtracting reaction times on compatible trials from those on incompatible trials. Pro-social priming produced a larger automatic imitation effect than anti-social priming, indicating that the relationship between mimicry and social attitudes is bidirectional, and that social attitudes have a direct and specific effect on the tendency to imitate behavior without intention or conscious awareness

A PARAMETRIC INVESTIGATION OF THE LUNAR-ORBIT-RENDEZVOUS SCHEME

Lunar orbit rendezvous scheme - mission analysi

Development during adolescence of the neural processing of social emotion

In this fMRI study, we investigated the development between adolescence and adulthood of the neural processing of social emotions. Unlike basic emotions (such as disgust and fear), social emotions (such as guilt and embarrassment) require the representation of another's mental states. Nineteen adolescents (10–18 years) and 10 adults (22–32 years) were scanned while thinking about scenarios featuring either social or basic emotions. In both age groups, the anterior rostral medial prefrontal cortex (MPFC) was activated during social versus basic emotion. However, adolescents activated a lateral part of the MPFC for social versus basic emotions, whereas adults did not. Relative to adolescents, adults showed higher activity in the left temporal pole for social versus basic emotions. These results show that, although the MPFC is activated during social emotion in both adults and adolescents, adolescents recruit anterior (MPFC) regions more than do adults, and adults recruit posterior (temporal) regions more than do adolescents