Effects of surface roughness on the intensity distribution of light reflected from aluminum surfaces

Only over the past few years have investigations of the intensity distribution of the light reflected from materials been attempted. Most of these investigations have been done by personnel at the National Bureau of Standards on matt surfaces, and acid etched black glass. It should be noted that separate investigations in the two fields, the methods of analysis of a surface\u27s topography and the intensity distribution of reflected light from different materials have been and still are being performed. However, most correlations which exist between a surface\u27s topography and its optical effects such as reflectance, intensity, absorption, and transmission are generally unknown. The purpose of this investigation is an attempt to correlate the roughness height and the intensity of the light reflected from 99.99% aluminum metal, hereafter simply referred to as aluminum metal, and to try to explain their meaning

Effects of the social environment during adolescence on the development of social behaviour, hormones and morphology in male zebra finches (Taeniopygia guttata)

Abstract Background Individual differences in behaviour are widespread in the animal kingdom and often influenced by the size or composition of the social group during early development. In many vertebrates the effects of social interactions early in life on adult behaviour are mediated by changes in maturation and physiology. Specifically, increases in androgens and glucocorticoids in response to social stimulation seem to play a prominent role in shaping behaviour during development. In addition to the prenatal and early postnatal phase, adolescence has more recently been identified as an important period during which adult behaviour and physiology are shaped by the social environment, which so far has been studied mostly in mammals. We raised zebra finches ( Taeniopygia guttata ) under three environmental conditions differing in social complexity during adolescence\ua0-\ua0juvenile pairs, juvenile groups, and mixed-age groups - and studied males\u2019 behavioural, endocrine, and morphological maturation, and later their adult behaviour. Results As expected, group-housed males exhibited higher frequencies of social interactions. Group housing also enhanced song during adolescence, plumage development, and the frequency and intensity of adult courtship and aggression. Some traits, however, were affected more in juvenile groups and others in mixed-age groups. Furthermore, a testosterone peak during late adolescence was suppressed in groups with adults. In contrast, corticosterone concentrations did not differ between rearing environments. Unexpectedly, adult courtship in a test situation was lowest in pair-reared males and aggression depended upon the treatment of the opponent with highest rates shown by group-reared males towards pair-reared males. This contrasts with previous findings, possibly due to differences in photoperiod and the acoustic environment. Conclusion Our results support the idea that effects of the adolescent social environment on adult behaviour in vertebrates are mediated by changes in social interactions affecting behavioural and morphological maturation. We found no evidence that long-lasting differences in behaviour reflect testosterone or corticosterone levels during adolescence, although differences between juvenile and mixed-age groups suggest that testosterone and song behaviour during late adolescence may be associated

One week in October: Luis Suárez, John Terry and the turn to racial neoliberalism in English men’s professional football

This article explores two significant incidents of racism – involving Luis Suárez and John Terry – from the 2011–2012 English Premier League football season. In particular, it analyses and contextualises the reactions and responses articulated by key stakeholders within the football industry. Discursive themes were employed by these individuals as a means of trying to mitigate and/or exonerate the actions of Suárez and Terry, to question the veracity of the allegations made against them, and to downplay the extent and effects of racism in English football more generally. The article situates these standpoints within the wider cultural politics of race in the game and extricates the connections between discourse and structure in manifestations of racism. It demonstrates that these dominant responses are indicative of colour-blind ideology, white racial framing and the rules of racial standing. It also argues that these sporting trends are part of a wider societal shift towards racial neoliberalism