19 results on '"Attwell, David"'
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2. Electric current flow in excitable tissues
- Author
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Attwell, David Ian
- Subjects
621.31 - Published
- 1978
3. P2Y13 receptors regulate microglial morphology, surveillance, and resting levels of interleukin 1β release
- Author
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Kyrargyri, Vasiliki, Madry, Christian, Rifat, Ali, Arancibia-Carcamo, Lorena I.L., Jones, Steffan S.P., Chan, Victor V.T.T., Xu, Yajing, Robaye, Bernard, Attwell, David, Kyrargyri, Vasiliki, Madry, Christian, Rifat, Ali, Arancibia-Carcamo, Lorena I.L., Jones, Steffan S.P., Chan, Victor V.T.T., Xu, Yajing, Robaye, Bernard, and Attwell, David
- Abstract
Microglia sense their environment using an array of membrane receptors. While P2Y12 receptors are known to play a key role in targeting directed motility of microglial processes to sites of damage where ATP/ADP is released, little is known about the role of P2Y13, which transcriptome data suggest is the second most expressed neurotransmitter receptor in microglia. We show that, in patch-clamp recordings in acute brain slices from mice lacking P2Y13 receptors, the THIK-1 K+ current density evoked by ADP activating P2Y12 receptors was increased by ~50%. This increase suggested that the P2Y12-dependent chemotaxis response should be potentiated; however, the time needed for P2Y12-mediated convergence of microglial processes onto an ADP-filled pipette or to a laser ablation was longer in the P2Y13 KO. Anatomical analysis showed that the density of microglia was unchanged, but that they were less ramified with a shorter process length in the P2Y13 KO. Thus, chemotactic processes had to grow further and so arrived later at the target, and brain surveillance was reduced by ~30% in the knock-out. Blocking P2Y12 receptors in brain slices from P2Y13 KO mice did not affect surveillance, demonstrating that tonic activation of these high-affinity receptors is not needed for surveillance. Strikingly, baseline interleukin-1β release was increased fivefold while release evoked by LPS and ATP was not affected in the P2Y13 KO, and microglia in intact P2Y13 KO brains were not detectably activated. Thus, P2Y13 receptors play a role different from that of their close relative P2Y12 in regulating microglial morphology and function., SCOPUS: ar.j, info:eu-repo/semantics/published
- Published
- 2019
4. Capillary pericytes regulate cerebral blood flow in health and disease
- Author
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Hall, Catherine N, Reynell, Clare, Gesslein, Bodil, Hamilton, Nicola B, Mishra, Anusha, Sutherland, Brad A, O'Farrell, Fergus M, Buchan, Alastair M, Lauritzen, Martin, Attwell, David, Hall, Catherine N, Reynell, Clare, Gesslein, Bodil, Hamilton, Nicola B, Mishra, Anusha, Sutherland, Brad A, O'Farrell, Fergus M, Buchan, Alastair M, Lauritzen, Martin, and Attwell, David
- Abstract
Increases in brain blood flow, evoked by neuronal activity, power neural computation and form the basis of BOLD (blood-oxygen-level-dependent) functional imaging. Whether blood flow is controlled solely by arteriole smooth muscle, or also by capillary pericytes, is controversial. We demonstrate that neuronal activity and the neurotransmitter glutamate evoke the release of messengers that dilate capillaries by actively relaxing pericytes. Dilation is mediated by prostaglandin E2, but requires nitric oxide release to suppress vasoconstricting 20-HETE synthesis. In vivo, when sensory input increases blood flow, capillaries dilate before arterioles and are estimated to produce 84% of the blood flow increase. In pathology, ischaemia evokes capillary constriction by pericytes. We show that this is followed by pericyte death in rigor, which may irreversibly constrict capillaries and damage the blood-brain barrier. Thus, pericytes are major regulators of cerebral blood flow and initiators of functional imaging signals. Prevention of pericyte constriction and death may reduce the long-lasting blood flow decrease that damages neurons after stroke.
- Published
- 2014
5. Said Before Said
- Author
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Elmarsafy, Ziad, Bernard, Anna, Attwell, David, Landry, Donna, Elmarsafy, Ziad, Bernard, Anna, Attwell, David, and Landry, Donna
- Abstract
Edward Said continues to fascinate and stir controversy, nowhere more than with his classic work Orientalism. Debating Orientalism brings a rare mix of perspectives to an ongoing polemic. Contributors from a range of disciplines take stock of the book's impact and appraise its significance in contemporary cultural politics and philosophy.
- Published
- 2013
6. Glial and neuronal control of brain blood flow
- Author
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Attwell, David, Buchan, Alastair M, Charpak, Serge, Lauritzen, Martin, Macvicar, Brian A, Newman, Eric A, Attwell, David, Buchan, Alastair M, Charpak, Serge, Lauritzen, Martin, Macvicar, Brian A, and Newman, Eric A
- Abstract
Blood flow in the brain is regulated by neurons and astrocytes. Knowledge of how these cells control blood flow is crucial for understanding how neural computation is powered, for interpreting functional imaging scans of brains, and for developing treatments for neurological disorders. It is now recognized that neurotransmitter-mediated signalling has a key role in regulating cerebral blood flow, that much of this control is mediated by astrocytes, that oxygen modulates blood flow regulation, and that blood flow may be controlled by capillaries as well as by arterioles. These conceptual shifts in our understanding of cerebral blood flow control have important implications for the development of new therapeutic approaches.
- Published
- 2010
7. Miro1 is a calcium sensor for glutamate receptor-dependent localization of mitochondria at synapses.
- Author
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MacAskill, Andrew F., Rinholm, Johanne E., Twelvetrees, Alison E., Arancibia-Carcamo, I. Lorena, Muir, James, Fransson, Åsa, Aspenström, Pontus, Attwell, David, Kittler, Josef T., MacAskill, Andrew F., Rinholm, Johanne E., Twelvetrees, Alison E., Arancibia-Carcamo, I. Lorena, Muir, James, Fransson, Åsa, Aspenström, Pontus, Attwell, David, and Kittler, Josef T.
- Abstract
Energy use, mainly to reverse ion movements in neurons, is a fundamental constraint on brain information processing. Trafficking of mitochondria to locations in neurons where there are large ion fluxes is essential for powering neural function. Mitochondrial trafficking is regulated by Ca2+ entry through ionotropic glutamate receptors, but the underlying mechanism is unknown. We show that the protein Miro1 links mitochondria to KIF5 motor proteins, allowing mitochondria to move along microtubules. This linkage is inhibited by micromolar levels of Ca2+ binding to Miro1. With the EF hand domains of Miro1 mutated to prevent Ca2+ binding, Miro1 could still facilitate mitochondrial motility, but mitochondrial stopping induced by glutamate or neuronal activity was blocked. Activating neuronal NMDA receptors with exogenous or synaptically released glutamate led to Miro1 positioning mitochondria at the postsynaptic side of synapses. Thus, Miro1 is a key determinant of how energy supply is matched to energy usage in neurons.
- Published
- 2009
- Full Text
- View/download PDF
8. The energy use associated with neural computation in the cerebellum
- Author
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Howarth, Clare, Peppiatt-Wildman, Claire M., Attwell, David, Howarth, Clare, Peppiatt-Wildman, Claire M., and Attwell, David
- Abstract
The brain's energy supply determines its information processing power, and generates functional imaging signals, which are often assumed to reflect principal neuron spiking. Using measured cellular properties, we analysed how energy expenditure relates to neural computation in the cerebellar cortex. Most energy is used on information processing by non-principal neurons: Purkinje cells use only 18% of the signalling energy. Excitatory neurons use 73% and inhibitory neurons 27% of the energy. Despite markedly different computational architectures, the granular and molecular layers consume approximately the same energy. The blood vessel area supplying glucose and O2 is spatially matched to energy consumption. The energy cost of storing motor information in the cerebellum was also estimated.
- Published
- 2009
9. Fiction beyond words : late style in J.M. Coetzee's Jesus trilogy
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Mudura, Diana, Attwell, David, and Chambers, Claire
- Abstract
This thesis looks at the paradoxical representation of non-verbal modes of communication in J.M. Coetzee's late works, focusing particularly on the trilogy formed by The Childhood of Jesus (2013), The Schooldays of Jesus (2016), and The Death of Jesus (2019). It uses the idea of the non-verbal as a reading strategy that enables the exploration of how characters communicate through music and dance, and with animals. Each chapter examines a specific dimension of language. Chapter 1 foregrounds an alternative form of language that echoes through the characters' mother tongue. In Chapter 2 the limits of what constitutes language are tested by Coetzee's imagining of a kind of human-animal communication that verges on the miraculous. Chapters 3 and 4 examine music and dance as aesthetic modes of intelligibility and communication. The aim of this engagement with Coetzee's use of language is to show that the trilogy reflects an existential dimension governed less strongly by the linguistic and more by a new connective tissue resulting from the subordination of ordinary language in favour of modes of communication that allow the reaching of a more fundamental experience of being in the world. These three novels epitomise Coetzee's experimentation with aesthetic, ethical, and affective experience that often resists verbalisation, while highlighting a form of pre-linguistic and pre-rational interconnectedness. The idea of the non-verbal is therefore crucial as a way of bringing to the forefront the underlying possibilities of communication and connection resulting from a conscious engagement with ordinary language and an inherent desire to transcend it that characterises Coetzee's late style.
- Published
- 2022
10. Black South African travel texts, c.1850-present : mobility, politics, writing
- Author
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Remmington, Catherine Janet and Attwell, David
- Abstract
This study is the first to analyze black South African literary and intellectual history through a lens of travel. It explores ways in which black writers, thinkers, activists, and ordinary citizens were - and continue to be - on the move, inscribing their mobilities. The thesis discusses wider, more varied histories and contemporary realities of travel and text in relation to South Africa than have generally been recognized. I argue that texts arising from, and speaking to, travel of various kinds are particularly salient given a significant thrust in South African history of politicizing, problematizing, and aiming to control black mobility and expression. The texts under study in relation to travel are necessarily multifarious and multiply inflected beyond 'travel writing' as conventionally understood by Anglo-American literary studies. Texts have arisen from a great variety of genres and modes, registering, valorizing, and interrogating forms of travel, as well as its metaphors, and addressing impositions to movement. I adopt an interdisciplinary methodology, bringing the literary-critical, historicist-archival, and geographic into conversation to explore the intersecting arenas of textuality and mobility under investigation. I examine black histories of text and travel in South Africa from the mid-19th century to the present day, with each of my four chapters adopting a thematic focus broadly tracking the chronological. I thus explore black South African travel texts over time through focusing, firstly, on their interests in shaping and stretching the Christian mission enterprise; secondly, on their claims to the nation and the world in relation to early-mid-20th-century modernity; thirdly, on their navigations of apartheid with a focus on women's exertions; and, lastly, on their explorations and interpretations of freedom post-apartheid. In sum, my thesis opens up dimensions of an under-recognized 'archive' of black texts born out of movement. It sheds new light on black histories of writing and ideas in relation to mobility; unsettles preoccupations with South Africa's boundedness in every sense; and fosters vital conversations about being black and on the move in the world today.
- Published
- 2020
11. Home and homecoming in Māori and Pacific literature, 1966-2004
- Author
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Schneidemesser, Lotta, Attwell, David, and Kingston-Reese, Alexandra
- Subjects
899 - Abstract
This thesis addresses the depiction of home and homecoming in a selection of short stories and novels by Patricia Grace, Witi Ihimaera and Albert Wendt, arguing that home and homecoming have emerged as key tropes in Māori literature from its earliest beginnings. This thesis builds on the argument that the Second World War brought about a significant change in the living conditions of Māori in New Zealand within just one generation, with many Māori moving away from traditional life to live in towns and cities. Many Māori experienced a profound loss of home and of their traditional community. I argue that this spurred a nostalgia for home and community that had to be written back into existence; the development of Māori literature, modernity, and the concept of home are closely interlinked. The term ‘home’ and its different facets and meanings in postcolonial literature have been partially explored by scholars such as Susheila Nasta and Rosemary George. However, little attention has to date been paid to the critical motif of homecoming and return migration. This thesis aims to address this gap in criticism by focusing on the moment of homecoming in selected short stories and novels. The overarching question this thesis poses is whether for the protagonists in these short stories and novels, a homecoming is possible, or whether it proves ultimately beyond reach. If this is the case, what follows then? A redefinition of one’s idea of home, and consequently, one’s identity? Or an acceptance that there is no going back? That in order to define a new sense of home one must create it anew. By forming a close reading of these short stories and novels against their historical context, and exploring how historical, political and cultural change at the time interlink with them, my thesis explores how the examination of the concepts of home and homecoming can contribute to our wider understanding of Māori and Pacific literature.
- Published
- 2019
12. The novel of liberal lament : reading identity in novels by Atwood, Coetzee, DeLillo, McEwan and Morrison in the period of liberal ascendancy (1989-2008)
- Author
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Lukey, Richard and Attwell, David
- Abstract
This thesis interprets a corpus of five novels and identifies a genre called the novel of liberal lament. The protagonists of Ian McEwan’s Saturday (2005), Don DeLillo’s Falling Man (2007), Margaret Atwood’s The Robber Bride (1993), J.M. Coetzee’s Disgrace (1999) and Toni Morrison’s Paradise (1997) are all recognisably liberal figures facing the heterogeneity of the world. The period in which these novels are written is one I call the period of liberal ascendancy, in which liberalism increases its influence internationally, despite challenges to its value system. In order to investigate the novels’ engagement with liberalism in the period, this thesis develops and demonstrates a reading model. This model prescribes two related areas of attention. The first involves Bakhtin’s chronotope, which is defined in relation to his idea of dialogic identity formation. A close reading that concentrates on the time-spaces of the novels as sites of dialogic identity formation is followed by a consideration of the novels in light of Rawls’s concept of public reason. The Rawlsian concept of formal debate as the basis for a democracy provides a closer focus on specific forms of dialogue that are part of the liberal tradition’s political prescription for social construction. What emerges from the reading is a tension in liberalism in the period between what is achieved and what might have been achieved. The first part involves a historical dramatisation of a liberalism that is economically strong and interpersonally weak. The second part involves a lament for a liberalism that might instead have been economically weak and interpersonally strong. Just as classical liberal economics is ascendant in the period, the liberal tradition of debate fails, but the novels imagine ways in which reimagined forms of debate might have made liberalism more responsive to the complexity of the world in the period.
- Published
- 2019
13. Home consciousness in the works of J.M. Coetzee
- Author
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Dong, Liang and Attwell, David
- Subjects
820 - Abstract
This thesis explores the literary representations of home consciousness in the works of J.M. Coetzee. Noting the historical and biographical origins of this concern in Coetzee's authorship, I am interested primarily in how home consciousness plays out in his texts. Tracing Coetzee's life through two recently published biographies, one written by J.C. Kannemeyer and the other by David Attwell, enables us to detect a sense of belonging and alienation in his way of addressing the issue of personal residence and national identification, which I refer to as a Janus-faced attitude to home. This striking feature in his authorship sheds light on the pervasive home consciousness in his fiction where characters wrestle with the tension of home, historically, culturally and ethically. I unpack my argument on this series of tensions in an eclectic approach. The introduction outlines the general theoretical foundation on which the thesis is premised, namely a frank account of authorship's importance in criticism, especially in Coetzee's case. After tracing Coetzee's Janus-faced attitude to home in the opening chapter, the thesis primarily considers one novel for discussion in each successive chapter. Chapter Two centres on how "The Narrative of Jacobus Coetzee" becomes an ethical challenge for Coetzee to narrate home consciousness. The third chapter focuses on Coetzee's hostile coexistence with censorship and how Magda from In the Heart of the Country grapples with home. My next chapter uses Freud's "The Uncanny" to investigate unhomely authorship and uncanny narrative in Waiting for the Barbarians. Chapter five revolves around the metaphorical landscapes in Life & Times of Michael K. The following chapter conducts a feminist reading of home consciousness in Age of Iron and the last chapter addresses Lurie's and Lucy's alternatives to home in Disgrace from a postsecular perspective. In the epilogue to the thesis, I propose three trajectories in the development of home consciousness in Slow Man and The Childhood of Jesus.
- Published
- 2018
14. 'Lean[ing] into transcendence' : transformations of the sacred in South African, Zimbabwean and Nigerian literatures
- Author
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Cumpsty, Rebekah Lindiwe Levitt and Attwell, David
- Subjects
820.9 - Abstract
Enchantment is a defining feature our postcolonial, globalised world and the literary is where much of this wonder is registered and celebrated. Thus this thesis attends to the postcolonial dynamic of sacred and secular experience as it is represented in contemporary African literatures. Debates around the secular and postsecular are long standing in the fields of religious studies, anthropology and philosophy, but as yet underappreciated in literary studies. I develop a hermeneutic of the imminent sacred as a way to read the constitutive and recuperative gestures subjects make as they assert a sense of belonging in spaces of globalised modernity. The texts are grouped thematically. In response to Chris Abani and Yvonne Vera’s work I articulate how the ritual dimensions of lyrical prose and ritual attention to the corporeal form sacralises the body. Phaswane Mpe and Teju Cole incorporate African epistemologies into the resignification of their cities and with Ivan Vladislavić, the streets are sacralised. Marlene van Niekerk and J. M. Coetzee convey the anxieties of settler colonialism and a love of land reinscribed as sublime. Collectively, the novels I discuss reflect patterns of existential anxiety that emerge from difficulties of belonging, and I trace the ritualised and sacralising strategies of incorporation that seek to locate the subject. These novels radically disrupt the epistemological and ontological modalities of globalised ‘secular’ literary production and intervene in the recuperation of the sacred as a mode of incorporation and resistance. Recent scholarship in African literatures has overlooked these distinctly postsecular negotiations and the ways in which the sacred is reinvested in contemporary African fiction in order to instantiate intimate, local alternatives to the teleology of secular modernity. Thus I use the imminent sacred as a reading strategy that foregrounds these postsecular negotiations and the interrelations of care and vulnerability that motivate sacralisation.
- Published
- 2016
15. Forging a new South Africa : plagiarism and the national imaginary
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Highman, K. B. and Attwell, David
- Subjects
820.90091 - Abstract
This thesis explores debates about plagiarism in post-apartheid South Africa, focussing on two highly-publicised cases, Antje Krog's Country of My Skull and Zakes Mda's The Heart of Redness. Through close reading, and by presenting such reading as culturally meaningful rather than forensic, I argue that in each text plagiarism acts as a contestation of cultural authority and a type of symbolic violence. Each text consciously affiliates itself to a particular literary tradition, occluding those sources that trouble the limits of these traditions, and re-appropriating cultural prestige. Re-establishing context illuminates the violent transculturations that underwrite South African cultural production and how national literatures are fields of contestation, rather than organically developing, self-contained formations. Chapter One considers the dispute between Stephen Watson and Krog over their respective poeticisations of |Xam narratives, contextualising it within a long history of appropriative white writing about indigenous peoples. Chapter Two considers Krog's alleged plagiarisms in Country of My Skull; notes other instances of unacknowledged copying; and relates Krog's borrowings to her use of testimony, arguing that a number of testimonies are fictionalised, and that Krog's borrowings and fictionalisations work together to lend her text a first-hand authenticity marked as specifically African. Chapter Three considers Mda's alleged plagiarism of Jeff Peires's The Dead Will Arise and notes how, contrary to Mda's claim that there is no written record for the Khoikhoi stories he retells in his novel, there is one, Theophilus Hahn's Tsuni-||Goam. Mda's borrowings serve to reinscribe an originary Xhosa identity, relatively uninflected by Christian,colonial influence, and to affiliate his work with African orature, rather than print culture. The afterword comments on the wider cultural and ethical implications of plagiarism; the ‘counter-narratives' that Krog and Mda's borrowings reveal; and the relationship of their borrowings to the metaphorical 'forging' of a 'new' South Africa in post-apartheid authorship.
- Published
- 2011
16. Prison and garden : Cape Town, natural history and the literary imagination
- Author
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Twidle, Hedley Lewis and Attwell, David
- Subjects
820.90091 - Abstract
This work considers literary treatments of the colonial encounter at the Cape of Good Hope, adopting a local focus on the Peninsula itself to explore the relationship between specific archives – the records of the Dutch East India Company, travel and natural history writing, the Bleek and Lloyd Collection – and the contemporary fictions and poetries of writers like André Brink, Breyten Breytenbach, Jeremy Cronin, Antjie Krog, Dan Sleigh, Stephen Watson, Zoë Wicomb and, in particular, J. M. Coetzee. Although it would hardly claim to be a literary history of Cape Town, it begins by asking what it might mean to read a history of the city through its literature. Yet moving beyond an initial enquiry into how (and at what cost) imaginative literature brings historical records into the public domain, it is ever more concerned with the writing in and of a specific topography: with the dynamics of rendering in words a landscape celebrated for its beauty and biodiversity, and with the wider social dimensions implied (or obscured) by the phrase ‘natural history’. It intends to question the received wisdom that attention to the landscape, flora and fauna of the subcontinent conceals an unwillingness to deal with social and political realities, probing the limits of this now well-trodden critical model to explore the limits of what Coetzee called ‘dream topographies’: ways of imagining contested ground that have shaped writing here, and the forms in which these persist today. Throughout I hope to suggest productive rather than antagonistic relations between what might broadly be termed ‘postcolonial’ and ‘ecocritical’ ways of reading, and to ask what, if anything, a ‘sense of place’ could mean in a spatially distorted, linguistically divided city of the global South.
- Published
- 2010
17. Aboriginal Britain : ethnological folkloristics and the origin of the nation in the work of Sir George Laurence Gomme, Sir John Rhŷs, and Alfred Nutt
- Author
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Lewis, Elinor Spalding, Attwell, David, and Townend, Matthew
- Subjects
820.9008 - Abstract
Through a close reading of the theoretical work of folklorists Sir George Laurence Gomme, Sir John Rhŷs, and Alfred Nutt and extensive research into the discourses of human and social origins in the nineteenth and early twentieth centuries, this thesis examines the use of folklore as a tool for the scientific interpretation of the history and identity of the nation. This thesis concentrates in particular on the emergence of indigeneity as a central concern for folklorists working with the archive of traditional lore and custom; through an extensive examination of Gomme, Rhŷs, and Nutt’s intellectual relationship, I trace the ways in which each identified and delineated a particular source for the national self. Finally, this thesis argues that the discourse of folklore was a key player in the formation of late nineteenth and early twentieth-century conceptions of national and racial history and demonstrates the extent to which an ethnological discourse, often considered solely in a colonial context, was central to the period’s interpretations of Britain’s national genealogy and historical identity. Part One demonstrates the pivotal role Sir George Laurence Gomme played in the development of folklore as a science and argues for the centrality of the discipline of folklore itself in late nineteenth and early twentieth-century ethnological discourse. Gomme’s theory of an indigenous, pre-Aryan racial inheritance in the development of British institutional history is also analyzed in detail, and the intellectual and popular genealogy of the idea of the pre-Aryan is given extensive examination. Part Two considers the work of Sir John Rhŷs and Alfred Nutt on Celtic language and folklore in the context of Gomme’s paradigm. Rhŷs’ use of folklore as a tool for philological research into the history of Britain is contextualized within intellectual developments in German and British linguistic research, and it is shown that the concept of a pre-Aryan indigenous race was central to his interpretation of European linguistic and racial history. Alfred Nutt’s research into the history and development of Celtic narrative and legend is contextualized to demonstrate his inheritance of continental scholarly discourses on Celtic folklore, and the significance of Nutt’s argument for a Celtic, rather than a non-Aryan indigeneity, is discussed in relation to both Gomme and Rhŷs’ interpretation of British prehistory. Finally, it is shown that Nutt imagined folklore to be an inherently imperialist project, and folklorists as the stewards of Britain’s subject nations’ racial-cultural archives; his views are examined in the context of early twentieth-century Irish nationalism and the Celtic Revival.
- Published
- 2010
18. The Cambridge History of South African Literature
- Author
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Attwell, David, editor and Attridge, Derek, editor
- Published
- 2012
- Full Text
- View/download PDF
19. Bury Me at the Marketplace: Es'kia Mphahlele and Company: Letters 1943-2006
- Author
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Manganyi, N. Chabani, editor and Attwell, David, editor
- Published
- 2009
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