A Numerical Simulation of Chern-Simons Inflation

In this work, we present results of numerical simulations of the Chern-Simons Inflation Model proposed by Alexander, Marciano and Spergel. According to this model, inflation begins with a fermion condensate interacting with a gauge field. Crucial to the success of this mechanism is the assumption that the Chern-Simons interaction would drive energy from the initial random spectrum into a narrow band of frequencies at superhorizon scales. In this work we numerically confirm this expectation. These gauge fields and currents, when combined with the Friedmann equations, were broken into a system of hyperbolic equations and numerically simulated. It was found in our simulation that, by including the effects of the chiral anomaly for the axial vector current, inflation ended satisfactorily after approximately 60 e-folds.Comment: 6 pages, 8 figure

The Stability of the orbits of Earth-mass planets in and near the habitable zones of known exoplanetary systems

We have shown that Earth-mass planets could survive in variously restricted regions of the habitable zones (HZs) of most of a sample of nine of the 93 main-sequence exoplanetary systems confirmed by May 2003. In a preliminary extrapolation of our results to the other systems, we estimate that roughly a third of the 93 systems might be able to have Earth-mass planets in stable, confined orbits somewhere in their HZs. Clearly, these systems should be high on the target list for exploration for terrestrial planets. We have reached this conclusion by launching putative Earth-mass planets in various orbits and following their fate with a mixed-variable symplectic integrator

The stability of orbits of putative Earth-mass planets or satellites of giant planets within known exoplanetary systems.

The movement of the habitable zone of 55 stars from 0.5 to 1.5 Solar masses and 0.75% to 5% metallicity were modelled over their main sequence lifetimes. 156 stars known to have planetary systems had their mass and metallicity matched to their nearest model, giving approximate habitable zones, which were compared with their giant planet(s)’s orbital range and gravitational reach. Habitable zones lying outside a giant’s gravitational reach for one billion years (two billion years after star birth) could host an Earth-mass planet in a stable confined orbit long enough for life to develop. Low eccentricity giant orbits confined to the habitable zone could also host Earth-mass satellites. Results show 85 of 156 exosystems could house a habitable Earth-mass body over the last billion years, 113 could do so for at least a billion years at sometime during their main sequence lifetimes, excluding the heavy bombardment period. An orbital integrator computer program modelled orbits of Earth-mass planets in the habitable zones of x1 Gruis, HD 196050, HD 52265, 55 Cancri, and Earth-mass giant planet satellites in HD 23079 and HD 28185. The integrator’s predictions for satellite orbits were shown to comply with restricted three-body problem theory. ‘Earths’ were ‘launched’ at different distances from the star or planet and their orbital parameters monitored with time until the program concluded after either one billion years, 100 million years, or a cataclysmic event. Orbits lasting the full run time are assumed to remain stable for the star’s main sequence lifetime. Results reveal the possibility of habitable Earth-mass planets around HD 52265, 55 Cancri, and satellites around the giants of HD 23079 and HD 28185. The x1 Gruis system cannot host a habitable ‘Earth’ whereas HD 196050 could, provided the planet’s semimajor axis was at the inner 20% of the habitable zone width

American socio-politics in fictional context: transformers and the representation of the United States

The fictional narratives that have been developed for the support of the Transformers brand, with their underlying emphasis on the sale of action figures, have been dismissed as a somewhat juvenile and uninteresting text. Little to no serious academic analysis of any of the various iterations of the franchise has been undertaken. With this thesis, I endeavour to begin that analysis and thus broaden and problematize the currently limited understanding of Transformers fictions. Due to the franchise’s vast nature, I focus on the original animation (1984-1987) and the recent live-action movies (2007-2011) with their attempts to offer a representation of the contemporaneous sociopolitical environment in America at the time of their production. In order to undertake this study, I combine my background in political analysis with film and media studies to seek out and explore the political themes and commentaries present in the key areas of political philosophy, technological change, the depiction of politicians, gender and sexuality, and America’s international role. Through this analysis of the franchise I shall construct an argument that Transformers is a complex narrative, replete with socio-political allegory that offers a representation of the United States and a view of itself in the arenas of domestic and global politics

Digestion of Protein in Premature and Term Infants.

Premature birth rates and premature infant morbidity remain discouragingly high. Improving nourishment for these infants is the key for accelerating their development and decreasing disease risk. Dietary protein is essential for growth and development of infants. Studies on protein nourishment for premature infants have focused on protein requirements for catch-up growth, nitrogen balance, and digestive protease concentrations and activities. However, little is known about the processes and products of protein digestion in the premature infant. This review briefly summarizes the protein requirements of term and preterm infants, and the protein content of milk from women delivering preterm and at term. An in-depth review is presented of the current knowledge of term and preterm infant dietary protein digestion, including human milk protease and anti-protease concentrations; neonatal intestinal pH, and enzyme activities and concentrations; and protein fermentation by intestinal bacteria. The advantages and disadvantages of incomplete protein digestion as well as factors that increase resistance to proteolysis of particular proteins are discussed. In order to better understand protein digestion in preterm and term infants, future studies should examine protein and peptide fragment products of digestion in saliva, gastric, intestinal and fecal samples, as well as the effects of the gut micro biome on protein degradation. The confluence of new mass spectrometry technology and new bioinformatics programs will now allow thorough identification of the array of peptides produced in the infant as they are digested

Habitability of known exoplanetary systems based on measured stellar properties

At present, because of observational selection effects, we know of no exoplanetary systems with any planetary masses close to that of the Earth. We have therefore used computer models to see whether such planets could be dynamically stable in the presence of the more massive planets known to be present, and in particular whether planets with roughly an Earth mass could remain confined to the classical habitable zone (HZ) for long enough for life to have emerged. Measured stellar properties have been used to determine for each system the present location of the HZ. We have also determined the critical distances from the orbit of each giant planet within which an Earth-mass planet would suffer large orbital changes. We then evaluated the present habitability of each and every exoplanetary system by examining the penetration of these critical distances into the HZ. The critical distances can be obtained by extensive computer modelling of an exoplanetary system. This is far too time consuming to apply to all of the 150 or so systems already known, and to keep up with the latest discoveries. Therefore, in earlier work we studied a few systems in great detail, and developed a speedier means of obtaining the critical distances. We summarize this comparatively quick method here. We can then evaluate comparatively quickly the present habitability of each exoplanetary system by examining the penetration of the critical distance(s) into the HZ. The results are encouraging for astrobiology.Comment: Accepted for publication by The Astrophysical Journal. A few revisions have been made following suggestions by the refere

Educational change and ICT: an exploration of priorities 2 and 3 of the DfES e-strategy in schools and colleges: the current landscape and implementation issues

Landscape review of integrated online support for learners and collaborative approaches to personalised learning activities

The Transformation of Gender in English-Language Fiction

Preprint to appear in a special issue of Cultural Analytics on "Identity." The article explores the paradox that the representation of gender in fiction became more flexible while the sheer balance of attention between fictional men and women was growing more unequal. We measure the rigidity of gendered roles by asking how easy it is to infer grammatical gender from ostensibly ungendered words used in characterization. In the nineteenth century, roles are so predictable that the inference is easy; it becomes harder as we move toward the present. But the diminishing power of stereotypes does not parallel progress toward equality of representation. On the contrary, by the middle of the twentieth century, women have lost almost half the space they occupied in nineteenth-century fiction. The tension between growing flexibility and growing inequality of representation presents literary historians with a striking paradox; a few potential explanations are considered