The wear of materials in an ash conditioner

Includes bibliographical references.The abrasive nature of fly ash handled in large coal-fired power stations results in unacceptable material and maintenance costs in ash-water mixing plant. Wear testing has been carried out in situ using a variety of generic materials. A ranking order of wear performance has been established both as a function of material and operating costs, and it has been demonstrated that impressive cost savings can be effected by the use of ceramic-coated steel mixing blades. The performance of such composites has been found to be sensitive to the design and method of application. To optimise materials selection, a family of tungsten carbide-cobalt cermets together with a number of structural ceramics were tested in situ. The modes of wear can be related to material constitution. By ranking the performance of these candidate materials, value based materials selection and design for use can be applied

Methacholine and PDGF activate store-operated calcium entry in neuronal precursor cells via distinct calcium entry channels

Neurons are a diverse cell type exhibiting hugely different morphologies and neurotransmitter specifications. Their distinctive phenotypes are established during differentiation from pluripotent precursor cells. The signalling pathways that specify the lineage down which neuronal precursor cells differentiate remain to be fully elucidated. Among the many signals that impinge on the differentiation of neuronal cells, cytosolic calcium (Ca2+) has an important role. However, little is known about the nature of the Ca2+ signals involved in fate choice in neuronal precursor cells, or their sources. In this study, we show that activation of either muscarinic or platelet-derived growth factor (PDGF) receptors induces a biphasic increase in cytosolic Ca2+ that consists of release from intracellular stores followed by sustained entry across the plasma membrane. For both agonists, the prolonged Ca2+ entry occurred via a store-operated pathway that was pharmacologically indistinguishable from Ca2+ entry initiated by thapsigargin. However, muscarinic receptor-activated Ca2+ entry was inhibited by siRNA-mediated knockdown of TRPC6, whereas Ca2+ entry evoked by PDGF was not. These data provide evidence for agonist-specific activation of molecularly distinct store-operated Ca2+ entry pathways, and raise the possibility of privileged communication between these Ca2+ entry pathways and downstream processes

Expression of microRNAs in cerebrospinal fluid of dogs with central nervous system disease

Abstract In this pilot study we investigated the expression of 14 microRNAs in the cerebrospinal fluid (CSF) of dogs with neoplastic, inflammatory and degenerative disorders affecting the central nervous system (CNS). CSF microRNA (miRNA) expression profiles were compared to those from dogs with neurological signs but no evidence of structural or inflammatory CNS disease. Seven miRNAs were easily detected in all samples: miR-10b-5p, miR-19b, miR-21-5p, miR-30b-5p, miR-103a-3p, miR-124, and miR-128-3p. Expression of miR-10b-5p was significantly higher in the neoplastic group compared to other groups. There was no relation between miRNA expression and either CSF nucleated cell count or CSF protein content. Higher expression of miR-10b-5p in the neoplastic group is consistent with previous reports in human medicine where aberrant expression of miR-10b is associated with various neoplastic diseases of the CNS

Border crossings in the African travel narratives of Ibn Battuta, Richard Burton and Paul Theroux

This article compares the representation of African borders in the 14th-century travelogue of Ibn Battuta, the 19th-century travel narrative of Richard Burton and the 21st-century travel writing of Paul Theroux. It examines the mutually constitutive relationship between conceptions of literal territorial boundaries and the figurative boundaries of the subject that ventures across borders in Africa. The border is seen as a liminal zone which paradoxically separates and joins spaces. Accounts of border crossings in travel writing from different periods suggest the historicity and cultural specificity of conceptions of geographical borders, and the way they index the “boundaries” of the subjects who cross them. Tracing the transformations in these conceptions of literal and metaphorical borders allows one to chart the emergence of the dominant contemporary idea of “Africa” as the inscrutable, savage continent

The body unbound: ritual scarification and autobiographical forms in Wole Soyinka’s Aké: the years of childhood

The scarification in Aké is invested with major significance apropos Soyinka’s ideas on African subjectivity. Scarification among the Yoruba is one of the rites of passage associated with personal development. Scarification literally and metaphorically “opens” the person up socially and cosmically. Personal formation and self-realization are enabled by the Yoruba social code brought into being by its mythology. The meaning of the scarification incident in Aké is profoundly different. Determined by the form of autobiography which creates a self-constituting subject, the enabling Yoruba sociocultural context is elided. The story of Soyinka’s personal development is allegorical of the story of the development of the modern African subject. For Soyinka, the African subject is a rational subject whose constitution precludes the splitting of the scientific and spiritual which is a consequence of the Cartesian rupture. The African subject should be open to other subjects and the object world. Subjectivity constituted by the autobiographical mode closes off the opening up symbolically signalled by scarification.Web of Scienc

Sexual and National Difference in the high-speed, popular surrealism of Tommy Handley and Ronald Frankau’s double acts, 1929-1936

This edited collection explores the representations of identity in comedy and interrogates the ways in which “humorous” constructions of gender, sexuality, ethnicity, religion, class and disability raise serious issues about privilege, ..

Téa Obreht’s Transnational Disremembering within the Mythical Realism of The Tiger’s Wife

This paper discusses Téa Obreht's 2010 novel The Tiger's Wife within the context of transmigrations and post-national conceptions of both the real and mythical translocality. Through analysis of Obreht’s discourse of disremembering, which is in Aleksandar Hemon’s definition a recognition of one’s own experience under the new narrative, the paper will explore the transnational dimensions of the Slavic-American identity of The Tiger’s Wife. The aim of this paper is to focus on the new understanding of transnational relationality as well as on a reconception of reality that disremembers Obreht’s or, on a larger scale, human experience within the mythical realism of The Tiger’s Wife.Keywords: transnationalism, the Slavic-American identity, disremembering, Aleksandar Hemon, Téa Obreht, The Tiger’s Wife, mythical realismTo disremember, according to Aleksandar Hemon, a celebrated Bosnian-American writer with an immigrant experience, is to recognize one’s own experience under the new narrative. He points out that it especially refers to the “people who have come through a form of actual, physical slaughter, and to the extent the construction of narrative is memory, then the narrative, for them, has to involve a quantity of amnesia. More amnesia that is involved in most narrative” (Interview by Richard Wirick). Disremembering blends non-fiction and fiction, genocide documentation and utopian imagery, and implies an alternative interpretation of reality. Hemon’s 2008 novel The Lazarus Project is a transnational project of disremembering. In The Lazarus Project, Hemon intertwines a double narrative of the multilayered parallel universes of the past and the present by following the narrator Vladimir Brik, a post-war Bosnian who lives in the United States, as he questions his life. Brik traces the story of Lazarus Averbuch, a young Jewish immigrant who is a survivor of the Kishinev pogrom in what is now Moldova, and an alleged anarchist. At the same time, Brik questions both the inner and outer aspects of his reality. In the first-person narrative, he explains that he needs to re-imagine what he could not retrieve, and to see what he could not imagine. For this reason, he disremembers his own experience within the story of Lazarus that also implies resurrection and a new birth story. This paper will analyze Téa Obreht’s evocative 2010 novel The Tiger's Wife from the point of view of a Hemonesque narrative concept of disremembering and, within the discourse, an Obrehtesque interaction of myth and truth