Mars: Seasonally variable radar reflectivity

The 1971/1973 Mars data set acquired by the Goldstone Solar System Radar was analyzed. It was established that the seasonal variations in radar reflectivity thought to occur in only one locality on the planet (the Solis Lacus radar anomaly) occur, in fact, over the entire subequatorial belt observed by the Goldstone radar. Since liquid water appears to be the most likely cause of the reflectivity excursions, a permanent, year-round presence of subsurface water (frozen or thawed) in the Martian tropics can be inferred

Luminosity Density of Galaxies and Cosmic Star Formation Rate from Lambda-CDM Hydrodynamical Simulations

We compute the cosmic star formation rate (SFR) and the rest-frame comoving luminosity density in various pass-bands as a function of redshift using large-scale \Lambda-CDM hydrodynamical simulations with the aim of understanding their behavior as a function of redshift. To calculate the luminosity density of galaxies, we use an updated isochrone synthesis model which takes metallicity variations into account. The computed SFR and the UV-luminosity density have a steep rise from z=0 to 1, a moderate plateau between z=1 - 3, and a gradual decrease beyond z=3. The raw calculated results are significantly above the observed luminosity density, which can be explained either by dust extinction or the possibly inappropriate input parameters of the simulation. We model the dust extinction by introducing a parameter f; the fraction of the total stellar luminosity (not galaxy population) that is heavily obscured and thus only appears in the far-infrared to sub-millimeter wavelength range. When we correct our input parameters, and apply dust extinction with f=0.65, the resulting luminosity density fits various observations reasonably well, including the present stellar mass density, the local B-band galaxy luminosity density, and the FIR-to-submm extragalactic background. Our result is consistent with the picture that \sim 2/3 of the total stellar emission is heavily obscured by dust and observed only in the FIR. The rest of the emission is only moderately obscured which can be observed in the optical to near-IR wavelength range. We also argue that the steep falloff of the SFR from z=1 to 0 is partly due to the shock-heating of the universe at late times, which produces gas which is too hot to easily condense into star-forming regions.Comment: 25 pages, 6 figures. Accepted version in ApJ. Substantially revised from the previous version. More emphasis on the comparison with various observations and the hidden star formation by dust extinctio

The Suez Crisis and British and French policy revaluations towards membership of the European Communities

This thesis attempts to demonstrate that, far from being of little or even no importance as some authors have argued, the 1956 Suez Crisis was an event of great significance to the evolution of British and French policies towards membership of the European Communities. It identifies a gap in the historiographies of the Suez Crisis and the European integration process, and seeks to fill it, while at the same time providing a new interpretation of the link between the two areas of historical focus. Using manuscript sources from English, French and American archives, as well as contemporary media articles and personal papers, it will present six ways in which Suez directly influenced the development of British and French policy towards the European Communities: by forcing the British government to review the country’s position in the world, by enhancing the career of Harold Macmillan, boosting that of Edward Heath, changing French attitudes towards the Common Market in late 1956, its role in the return to power of General de Gaulle, and the development of the French nuclear deterrent. It will conclude that not was Suez a significant factor, but that without it, there may not be a European Union today

Book reviews

Teaching/Communication/Extension/Profession,

Operating experience with four 200 kW Mod-0A wind turbine generators

The windpowered generator, Mod-0A, and its advantages and disadvantages, particularly as it affects reliability, are discussed. The machine performance with regard to power availability and power output is discussed

The sound of violets: the ethnographic potency of poetry?

This paper takes the form of a dialogue between the two authors, and is in two halves, the first half discursive and propositional, and the second half exemplifying the rhetorical, epistemological and metaphysical affordances of poetry in critically scrutinising the rhetoric, epistemology and metaphysics of educational management discourse. Phipps and Saunders explore, through ideas and poems, how poetry can interrupt and/or illuminate dominant values in education and in educational research methods, such as: • alternatives to the military metaphors – targets, strategies and the like – that dominate the soundscape of education; • the kinds and qualities of the cognitive and feeling spaces that might be opened up by the shifting of methodological boundaries; • the considerable work done in ethnography on the use of the poetic: anthropologists have long used poetry as a medium for expressing their sense of empathic connection to their field and their subjects, particularly in considering the creativity and meaning-making that characterise all human societies in different ways; • the particular rhetorical affordances of poetry, as a discipline, as a practice, as an art, as patterned breath; its capacity to shift phonemic, and therewith methodological, authority; its offering of redress to linear and reductive attempts at scripting social life, as always already given and without alternative

The Correlation Between Galaxy HI Linewidths and K' Luminosities

The relationship between galaxy luminosities and rotation rates is studied with total luminosities in the K' band. Extinction problems are essentially eliminated at this band centered at 2.1 micron. A template luminosity-linewidth relation is derived based on 65 galaxies drawn from two magnitude-limited cluster samples. The zero-point is determined using 4 galaxies with accurately known distances. The calibration is applied to give the distance to the Pisces Cluster (60 Mpc) at a redshift in the CMB frame of 4771 km/s. The resultant value of the Hubble Constant is 81 km/s/Mpc. The largest sources of uncertainty arises from the small number of zero-point calibrators at this time at K' and present application to only one cluster.Comment: 13 pages including 5 figures and 2 tables. Accepted for publication in Astrophysical Journa

Widowhood and cognitive decline in adults aged 50 and over: A systematic review and meta-analysis

While widowhood is known to be associated with poorer physical and mental health outcomes, studies examining the association of widowhood with cognition have yielded mixed results. This review aimed to elucidate the link between widowhood and cognitive decline. A systematic search of Medline, Embase, PsycInfo, CINAHL and Scopus (until December 2020) was conducted to identify studies on the association between widowhood (vs. being married) and cognition in cognitively healthy adults aged 50 +. A cross-sectional meta-analysis (of 10 studies; n = 24,668) found a significant association of widowhood with cognition (g = − 0.36, 95% CI [− 0.47, − 0.25], p = < 0.001). Meta-regressions suggested that study design, cognitive domain measured, sample age, difference in mean age between widowed and married groups, and study continent did not account for observed heterogeneity. A longitudinal meta-analysis (of 3 studies; n = 10,378) found that the “continually widowed” group (from baseline to follow-up) showed significantly steeper declines in cognition compared to the “continually married” group (g = − 0.15, 95%CI [− 0.19, − 0.10], p = < 0.001). Findings indicate that widowhood may be a risk factor for cognitive decline. As there are no effective treatments for cognitive impairment, studying mechanisms by which widowhood might be associated with poorer cognition could inform prevention programs for those who have experienced spousal bereavement