Structural properties and quasiparticule energies of cubic SrO, MgO and SrTiO3

The structural properties and the band structures of the charge-transfer insulating oxides SrO, MgO and SrTiO3 are computed both within density functional theory in the local density approximation (LDA) and in the Hedin's GW scheme for self-energy corrections, by using a model dielectric function, which approximately includes local field and dynamical effects. The deep valence states are shifted by the GW method to higher binding energies, in very good agreement with photoemission spectra. Since in all of these oxides the direct gaps at high-symmetry points of the Brillouin zone may be very sensitive to the actual value of the lattice parameter a, already at the LDA level, self-energy corrections are computed both at the theoretical and the experimental a. For MgO and SrO, the values of the transition energies between the valence and the conduction bands are improved by GW corrections, while for SrTiO3 they are overestimated. The results are discussed in relation to the importance of local field effects and to the nature of the electronic states in these insulating oxides.Comment: 3 figures, accepted in J. Phys.: Condens. Matte

Full Sky Study of Diffuse Galactic Emission at Decimeter Wavelengths

A detailed knowledge of the Galactic radio continuum is of high interest for studies of the dynamics and structure of the Galaxy as well as for the problem of foreground removal in Cosmic Microwave Background measurements. In this work we present a full-sky study of the diffuse Galactic emission at frequencies of few GHz, where synchrotron radiation is by far the dominant component. We perform a detailed combined analysis of the extended surveys at 408, 1420 and 2326 MHz (by Haslam et al. 1982, Reich 1982, Reich & Reich, 1986 and Jonas et al. 1998, respectively). Using the technique applied by Schlegel et al. (1998) to the IRAS data, we produce destriped versions of the three maps. This allows us to construct a nearly-full-sky map of the spectral index and of the normalization factor with sub-degree angular resolution. The resulting distribution of the spectral indices has an average of beta = 2.695 and dispersion sigma_{beta} = 0.120. This is representative for the Galactic diffuse synchrotron emission, with only minor effects from free-free emission and point sources.Comment: 10 pages, 16 jpeg figures, accepted to Astronomy & Astrophysics, Comments and figure adde

Subjectivities in motion: Dichotomies in consumer engagements with self-tracking technologies

With the rise of self-tracking technologies (STT), self-quantification has become a popular digital consumption phenomenon. Despite recent academic interests, self-tracking practices remain poorly understood, in particular, little is known on how consumers engage with STT and how such behavioural trends produce new subjectivities. This paper adopts a Foucauldian perspective of self-surveillance to explore: how do subjectivities emerge from consumer interactions and engagements with self-tracking technologies? Data were collected from twenty participants using an ethnographic research design over six months consisting of semi-structured interviews and participant observation. The findings reveal two sets of dichotomies in the way consumers engage with STT, categorised as: ‘health and indulgence’ and ‘labour and leisure’. Through these dichotomies of self-surveillance, four subjectivities emerged: ‘redemptive self’, ‘awardee’, ‘loyal’ and ‘innovator’. Our study presents subjectivities as a continual process of (re)configuration of the self, as consumers move from one dichotomy to another. At the practical level, our findings offer novel approaches to segment consumers by reviewing the different contours of consumer behaviour in their interactions with STT

Away from home: how young Chinese consumers travel with global brands?

This interpretive study investigates how a group of young Chinese students consume global brands of American origins, in China and in the UK. More specifically, this research examines how meanings attached to global food brands travel abroad with consumers and investigates the relationship between brand consistency and brand meanings across national boundaries. Findings from a thematic analysis of focus group interviews conducted over a nine-month period, reveal that some brand meanings are context and culture specific (contextual meanings) while other meanings travel with consumers across borders (core meanings). Theoretically, this study shows how global brands provide a platform of structural meanings, ideas and practices that are global and globalising in themselves, allowing a degree of fluidity and adaptation in relation to the local context of consumption

Family practices and temporality at breakfast: hot spots, convenience and care

Drawing on 34 semi-structured interviews, this study investigates the temporality of family practices taking place in the hot spot (Southerton, 2003). It does so by looking at how breakfast is inserted in the economy of family time in Italy. Our data show that breakfast, contrary to other meals, allows the adoption of more individualised and asynchronous practices, hinged on the consumption of convenience products. These time-saving strategies are normalised as part of doing family. Although the existing literature suggests that convenience and care are in opposition, and consumers of convenience products can experience anxiety and a lack of personal integrity, such features were not a dominant feature of our participants’ accounts. These findings suggest that the dichotomies of hot/cold spots and care/convenience are not always experienced in opposition when embedded within family practices. Hence, this study furthers understandings of family meals, temporality and the distinction between hot and cold spots

Intensive Grandmothering? Exploring the Changing Nature of Grandmothering in the Context of Changes to Parenting Culture

This paper explores the ways in which the intensification of parenting and the notion of children at risk have influenced grandmothers’ narratives and practices. Interviews with grandmothers who regularly look after their grandchildren, reveal that their practices are framed around the notions of children to be protected, educated and entertained. Such notions reveal that aspects of grandmothers’ roles as protectors, educators, playmates and confidants involved negotiations with parents around the ideal of ‘putting the child first’. The paper argues that intensive parenting has influenced grandmothering but the way this is enacted reveals resistance to certain aspects of intensive parenting

Primary School Children’s Responses to Food waste at School

Purpose: This paper seeks to understand children’s responses to food waste in school by exploring children’s view on food waste and empowering them to discuss and develop their own solutions. Design/methodology/approach: Using creative problem-solving approach and photo voice technique, we conducted focus group discussions with 28 primary school children in the UK. Findings: Children have a clear understanding of the consequences of food waste for individuals, society, and the environment. They displayed negative emotions concerning food waste and responded positively to the possibility of food recycling. Their solutions to reduce food waste will require multiple stakeholder engagement, including self-regulation, peer-monitoring, teacher supervision and family support. However, rather than relying on intervention schemes that require significant adult involvement, children placed a heavy emphasis on self-regulation, playing an active role in addressing food waste in school. Originality: This research extends previous understanding, by showing children as agentic consumers that can shape food waste solutions in school. These findings are of use to primary teachers and local education authorities, to aid children in developing their own solutions to reduce food waste in their own schools

Right Taste, Wrong Place’: Local Food Cultures, (Dis)identification and the Formation of Middle-class Identity

This article investigates how culinary taste contributes to the formation of middle class identity in a working class context in the UK. We explore practices of food consumption among a group of individuals working at a UK university located in a working class city. We find a rather limited and discrepant cosmopolitanism, in which culinary practices are evaluated in terms of those worth engaging in, and those not worth engaging in, based on their ‘user friendliness’ for cosmopolitan middle class dispositions. Depictions of the local food culture as lacking are also dominant, used as a negative ground against which these dispositions are hierarchically formulated. Here middle class culinary tastes seem to be driven by disengagement with the wrong sort of place and a relatively closed alignment with the ‘proper’ and the ‘safe’ rather than by any open creative individuality

Huge excitonic effects in layered hexagonal boron nitride

The calculated quasiparticle band structure of bulk hexagonal boron nitride using the all-electron GW approximation shows that this compound is an indirect-band-gap semiconductor. The solution of the Bethe-Salpeter equation for the electron-hole two-particle Green function has been used to compute its optical spectra and the results are found in excellent agreement with available experimental data. A detailed analysis is made for the excitonic structures within the band gap and found that the excitons belong to the Frenkel class and are tightly confined within the layers. The calculated exciton binding energy is much larger than that obtained by Watanabe {\it et al} using a Wannier model to interpret their experimental results and assuming that h-BN is a direct-band-gap semiconductor.Comment: 4 pages, 3 figure