FUNCTIONAL ANALYSIS OF VIRAL SCHLAFEN FROM CAMELPOX VIRUS

This thesis concerns gene 176R from camelpox virus (CMLV) that encodes a protein known as viral schlafen (v-slfn). v-slfn has an N-terminal domain related to the p26 protein from baculovirus and a C-terminal domain related to mammalian schlafen proteins. A full length v-slfn is expressed by all sequenced orthopoxviruses except vaccinia virus (VACV) and variola virus. The baculovirus p26 proteins are poorly characterised, with no known function. In contrast, murine schlafen (m-slfn) proteins are upregulated in response to infection and the promoter for m-slfn2 has NF-κB and AP-1 binding sites. The prototypic slfn, m-slfn1, halts cellular proliferation by inhibition of cyclin D1 expression in vitro and both m-slfn1 and m-slfn8 reduce thymocyte proliferation in vivo. v-slfn is a predominantly cytoplasmic protein of 57 kDa that is expressed both early and late during CMLV infection. Expression of v-slfn reverses the growth arrest resulting from m-slfn1 expression, and this is a result of a reversal of the inhibition of cyclin D1 expression. This effect can be seen following overexpression of various transcription factors that upregulate cyclin D1 expression. Recombinant VACV expressing enhanced levels of v-slfn replicated and spread at a comparable rate to control viruses in vitro, but was less virulent than controls in the intranasal model of infection in vivo. A group of viruses based on VACV WR were constructed, which lack the gene fragments (B2R and B3R) corresponding to CMLV 176R. The undisrupted sequence for 176R was also re-inserted at this locus, resulting in a virus that expresses v-slfn from its natural promoter. In vitro characterisation showed no differences in replication or spread when compared to controls. Thus, v-slfn is an orthologue of mammalian slfn proteins, and may exert its effect by reversing their inhibition of cellular proliferation

Heavy fermions and magnetic order

Imperial Users onl

Telling the story of climate change:the German novel in the Anthropocene

This essay begins by discussing the implications of the Anthropocene for literature and literary criticism, and the part which ecocritics can play in critically analysing cultural representations of our relationship with nature and defining the contribution of imagination, art and writing to the development of a posthuman identity. Reviewing studies of climate fiction in English and German to date, it traces the emergence of climate fiction as a 21st-century genre, and presents a brief overview of 25 German novels published since 1993. Finally, it compares the solutions to problems of form and narrative strategy arrived at by Ilija Trojanow in his lament over our destructive impact on nature in Eistau (2011) with those in Cornelia Franz’s young adult novel, Ins Nordlicht blicken (2012)

Heavy Metal Toxicity in Bioremediation: Microbial Cultures and Microscopy

This research employed a variety of microscopy and spread plating techniques to observe the effects of heavy metal treatments on a toluene-selected bacterial population. Microbial colonies were cultured on spread plates and the resulting numbers were compared to respiration data. The mechanisms of reproduction were demonstrated to be more sensitive to metal treatments than were the mechanisms of respiration. Phase contrast, Gram stain, fluorescent microscopy, were used to compare and document a wide variety of bacteria resulting from different metal treatments as well as from environmental changes within the source bioreactor. The removal of sensitive bacteria and the selection of metal tolerant species resulting from metal treatments was observed. Species that were initially unobserved within the bioreactor appeared dominate when competing types of bacteria were removed and more agreeable environmental conditions were present. The use of fluorescent stains to differentiate between live and dead bacteria when treated with heavy metals proved to be impractical as the bacteria exhibited auto-fluorescence. Such new findings, however, did aid in the characterization of different types of bacteria and offered new techniques for potential heavy metal toxicity measurements as well as differentiation methods