505 research outputs found
Upper limits on K-band polarization in three high-redshift radio galaxies: LBDS 53W091, 3C 441 and MRC 0156-252
We present the results of K-band imaging polarimetry of three radio galaxies,
including the very red and apparently old z=1.55 galaxy 53W091. We find weak
evidence for polarization in components of 3C 441 and in the south-east
companion of 53W091, but no evidence of significant polarization in 53W091
itself. We also find strong evidence that MRC 0156-252 is unpolarised. We
present upper limits for the K-band polarization of all three sources. For
53W091, the lack of significant K-band polarization provides further confidence
that its red R-K colour can be attributed to a mature stellar population,
consistent with the detailed analyses of its ultraviolet spectral-energy
distribution which indicate a minimum age of 2-3.5 Gyr.Comment: 7 pages, 3 postscript figures. In press at MNRA
Platform Capitalism: The Intermediation and Capitalization of Digital Economic Circulation
A new form of digital economic circulation has emerged, wherein ideas, knowledge, labour and use rights for otherwise idle assets move between geographically distributed but connected and interactive online communities. Such circulation is apparent across a number of digital economic ecologies, including social media, online marketplaces, crowdsourcing, crowdfunding and other manifestations of the so-called âsharing economyâ. Prevailing accounts deploy concepts such as âco-productionâ, âprosumptionâ and âpeer-to-peerâ to explain digital economic circulation as networked exchange relations characterised by their disintermediated, collaborative and democratising qualities. Building from the neologism of platform capitalism, we place âthe platform' â understood as a distinct mode of socio-technical intermediary and business arrangement that is incorporated into wider processes of capitalisation â at the centre of the critical analysis of digital economic circulation. To create multi-sided markets and coordinate network effects, platforms enrol users through a participatory economic culture and mobilise code and data analytics to compose immanent infrastructures. Platform intermediation is also nested in the ex-post construction of a replicable business model. Prioritising rapid up-scaling and extracting revenues from circulations and associated data trails, the model performs the structure of venture capital investment which capitalises on the potential of platforms to realise monopoly rents
Capitalizing on the crowd: The monetary and financial ecologies of crowdfunding
âCrowdfundingâ is a method of raising money and finance to capitalize projects of various kinds. Drawing on the networking capabilities of the internet and software platforms, those seeking project funding appeal to potentially diverse audiences who are collectively referred to as âthe crowdâ. What practitioners, advocates and policymakers typically identify within crowdfunding is its âalternativeâ, âdisruptiveâ and âdemocratizingâ qualities; that is, it is held to be a novel, digitally rendered economic space which has the capacity to challenge established funding practices in banking, capital markets and venture capital networks, offering a more open and egalitarian source of capital for economic, social and cultural entrepreneurship. The paper develops the concept of âecologiesâ, drawn from the geographies of money and finance literature, to advance a critical understanding of the crowdfunding economy that is sceptical of its apparent qualities. First, by encouraging the analysis of diverse and proliferative monetary and financial forms, the concept of ecologies enables an understanding that avoids the binary opposition of âcapitalist/alternativeâ economic forms and which differentiates between the variegated crowdfunding ecologies that have emerged to date. Second, by foregrounding the intermediation processes and creditâdebt relations of monetary and financial ecologies, it is argued that crowdfunding may largely replicate rather than disrupt the extant institutional and debt dynamics of funding practices. Third, by emphasizing the socio-spatial effects of monetary and financial ecologies, attention is drawn to the need for further research into the unevenness that mitigates against crowdfunding being as open and egalitarian as its advocates claim
K-band polarimetry of seven high-redshift radio galaxies
We present the results of K-band imaging polarimetry of seven 3CR radio galaxies at redshifts (z) between 0.7 and 1.2. We find strong evidence for polarization in three sources: 3C 22, 3C 41 and 3C 114. Of these, 3C 41 shows strong evidence of having a quasar core whose infrared light is scattered by dust. We also find some evidence for polarization in 3C 54 and in 3C 356. The two pointlike sources (3C 22 and 3C 41) and the barely-elongated 3C 54 appear to have of order ten per cent of their K-band flux contributed by scattered light from the active nucleus. We conclude that scattered nuclear light can form a significant component of the near-infrared light emitted by high-redshift radio galaxies,and discuss models in which the scattering particles are electrons and dust-grains
An Integrated Study of the Morphological and Gross-Elemental Consequences of Methyl Mercury Intoxication in Rats, with Particular Attention on the Cerebellum
Methylmercury accumulates in the kidney and liver of rats, but fairly selectively damages the cerebellum, resulting in the clinical symptoms of neurological ataxia after prolonged exposures. Within the cerebellum, morphological examination indicated that the small granule cells beneath the Purkinje layer are especially susceptible to the toxin, showing signs of pyknosis during the phase of locomotory disability, whilst the large Purkinje cells are relatively resistant to cytotoxic injury. Flame photometric and electron probe X-ray microanalysis (EPXMA) of digested samples of the major organs failed to detect any significant changes in the Na, K, Ca, Mg, S and P concentrations of the organs, including the cerebellum, at intervals after methylmercury administration by either gastric gavage or via the drinking water. It was suggested that if the lesion within the cerebellum is restricted, as the morphological evidence suggests, to a small cohort of functionally important granule cells, then it may be difficult to detect elemental changes within this subpopulation against the compositionally unaltered majority of cerebellar cells and their extracellular spaces. To identify and compositionally characterize the injured cells requires electron probe X-ray microanalysis of frozen sections, or fractured bulk samples. The deep-seated nature of the \u27target cells\u27 within the cerebellum presents formidable cryopreparative problems
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Economic geography I: uneven development, âleft behind placesâ and âlevelling upâ in a time of crisis
This article is the first of three reviews in which economic geography is viewed through the lens of crises. This article focuses on the resurgence of uneven development as a political problem, which has led to public policy debates and responses in which economic geography is an underpinning construct. The article focuses on the UK where public policy responses have engaged with the problems caused by uneven development. Arguments made over many years about the long-term damaging impacts of geographical inequalities in opportunity and income have broken through into the political mainstream and gained traction. The article explains how this happened, as an already unbalanced regional economy was exacerbated first through growth led by financial services and then austerity-led decline. There are opportunities for economic geography in this public policy conjuncture, although it will require an ability to engage competently and critically with mainstream economics, and a willingness to work with political actors and a challenging, frustrating, and uncomfortable political process. Moreover, it also requires that the problem of uneven development remains adequately defined and attended to, so that appropriate public policy responses may be formulated, and continues to garner sufficient political attention, to allow both time and opportunity for intervention in public policy
Economies of space and the school geography curriculum
This paper is about the images of economic space that are found in school curricula. It suggests the importance for educators of evaluating these representations in terms of the messages they contain about how social processes operate. The paper uses school geography texts in Britain since the 1970s to illustrate the different ways in which economic space has been represented to students, before exploring some alternative resources that could be used to provide a wider range of representations of economic space. The paper highlights the continued importance of understanding the politics of school knowledge
âThis is awesome Miss. It is safe. We donât do this with any other teacher.â Classroom activities to listen to pupilsâ voices
This methodological paper is concerned with the use of âchild-centredâ methods to gather data from young people about their leisure lives. Specifically, a set of activities were devised that enabled young peopleâs voices to be heard, and their lived experiences to be understood. Inspired by research undertaken in primary schools, classroom-based activities which included creative representation, mind-mapping, pupil interaction and role play were used in a series of ethnographic case studies as part of a national secondary school physical activity research project in Wales during 2007-2009. This paper is an
exposition of these activities for researchers and professional practitioners to gather information. Through an evaluation of their efficacy with the young people themselves, the methods were found to be effective for data capture and as a focal point for subsequent interviewing and focus group discussions. They also engaged the young people and enabled rapport to be developed between the researcher and the researched. The success of these methods in specific educational settings has implications for teacher-researchers and professional practice with children and young people in other contexts
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