Blood on the Snow, Soot on the Carpet: Belief as Pedagogy in Terry Pratchett’s \u3ci\u3eHogfather\u3c/i\u3e

In Terry Pratchett’s Discworld novels, children largely refuse to conform to the ideas that adults form about them as a class. While the adults of the Discworld seem to regard childhood as a time of innocence and wonder, the children who inhabit Pratchett’s universe show themselves to be violent, cynical, manipulative, and naturally skeptical of any phenomena which they cannot directly sense. As such, when the beloved seasonal figure of the Hogfather, a former Winter Solstice deity transformed over time into a gift-giving fat man with a taste for sherry and pork-pies, is assaulted by entities who want to make human beings less fanciful, the Discworld’s anthropomorphic representation of Death takes it upon himself to keep up the pretense that the Hogfather is alive, well, and making his usual rounds. This is necessary because, as the novel argues, belief in fantasies is necessary for children to grow into functional adults – the child must start by believing in something relatively concrete, like a jolly fat man who delivers toys to children who behave themselves all year, in order to believe in abstract concepts like ‘justice’ and ‘mercy.’ Belief in figures like the Hogfather tempers the natural cruelty of children, teaching them how to live in harmony with one another as adults, but this belief must be encouraged through empirical evidence, since the children’s natural skepticism leads them to see through the pleasant illusions conjured for them by adults

“Like the tombs of nameless kings”: Louis MacNeice’s Western Anti-Pastoral

Throughout his career as a poet, Louis MacNeice, born in Belfast but schooled and resident in England, looks at the western counties of Ireland, and indeed the island itself, as a repository of historical memory, including the western Irish roots of his own family. While the east – that is, continental Europe – is embroiled in the Spanish Civil War and the coming Second World War and is thus seen as a site of significant contemporary action in MacNeice’s work, what action takes place in western Ireland tends to be in the past; both celebratory poems like the “Sligo and Mayo” and “Galway” parts of “The Closing Album”, parts 06 and more ambivalent pieces like “Valediction” and “Neutrality” stress an attachment to the past bred by insularity. Ireland’s concerns, to the expatriate MacNeice, are exclusively local and rooted in ancient history. The Irish Sea separates the island from the broader currents of European history, and it becomes an attraction for tourists from across the water, as noted in “Valediction”. Ireland – particularly the cultural nationalist ideal promoted by the Revival – is a kind of archive, but it is one which has become obscure, as indicated by “the tombs of nameless kings” (CP 181) in “Sligo and Mayo”. The holiday visitors who come to look into the past can no longer comprehend it, as the rest of the world has moved on. The pastoral modes that Yeats and his immediate successors applied to the west of Ireland obscure the violence of the present in favor of an idealized past that MacNeice cannot endorse.Le poète Louis MacNeice est né à Belfast, mais il fut éduqué et vécut en Angleterre. Tout au long de sa carrière, il insiste sur le fait que les comtés de l’ouest de l’Irlande – et l’île toute entière – sont imprégnés d’une histoire qui embrasse ses propres racines familiales dans l’Ouest. Alors que l’Est, c’est-à-dire l’Europe continentale, doit composer avec la Guerre civile en Espagne et les tourments de la Deuxième Guerre mondiale, MacNeice ancre cette Europe dans une réalité contemporaine où se déroulent d’intenses débats. À l’inverse, le travail de MacNeice évoque l’Ouest de l’Irlande par le recours au passé. Les poèmes “Sligo and Mayo”, “Galway”, qui font partie de “The Closing Album”, ainsi que “Valediction” et “Neutrality”, racontent tous l’histoire d’une Irlande insulaire et révolue. Les préoccupations de cette Irlande, selon MacNeice l’expatrié, sont de nature locale et font référence à des temps anciens. La mer d’Irlande qui isole l’île de l’histoire européenne est prisée par les touristes, comme l’auteur le note dans “Valediction”. L’Irlande – particulièrement l’idéal du nationalisme culturel au temps du Revival - est une archive obscure qui est devenue aussi illisible que “the tombs of nameless kings” (CP 181) de son poème “Sligo and Mayo”. Les touristes qui veulent découvrir son passé n’arriveront pas à la comprendre puisque le reste du monde est déjà passé à autre chose. Il en résulte que les représentations bucoliques de l’Ouest de l’Irlande que cultivèrent Yeats et ses successeurs immédiats obscurcissent les violences contemporaines au profit d’une version idéalisée du passé que MacNeice ne peut partager

B Cell Depletion in HIV-1 Subtype A Infected Ugandan Adults: Relationship to CD4 T Cell Count, Viral Load and Humoral Immune Responses

To better understand the nature of B cell dysfunctions in subjects infected with HIV-1 subtype A, a rural cohort of 50 treatment-naïve Ugandan patients chronically infected with HIV-1 subtype A was studied, and the relationship between B cell depletion and HIV disease was assessed. B cell absolute counts were found to be significantly lower in HIV-1+ patients, when compared to community matched negative controls (p<0.0001). HIV-1-infected patients displayed variable functional and binding antibody titers that showed no correlation with viral load or CD4+ T cell count. However, B cell absolute counts were found to correlate inversely with neutralizing antibody (NAb) titers against subtype A (p = 0.05) and subtype CRF02_AG (p = 0.02) viruses. A positive correlation was observed between subtype A gp120 binding antibody titers and NAb breadth (p = 0.02) and mean titer against the 10 viruses (p = 0.0002). In addition, HIV-1 subtype A sera showed preferential neutralization of the 5 subtype A or CRF02_AG pseudoviruses, as compared with 5 pseudoviruses from subtypes B, C or D (p<0.001). These data demonstrate that in patients with chronic HIV-1 subtype A infection, significant B cell depletion can be observed, the degree of which does not appear to be associated with a decrease in functional antibodies. These findings also highlight the potential importance of subtype in the specificity of cross-clade neutralization in HIV-1 infection

Memory B Cell Antibodies to HIV-1 gp140 Cloned from Individuals Infected with Clade A and B Viruses

Understanding the antibody response to HIV-1 in humans that show broad neutralizing serologic activity is a crucial step in trying to reproduce such responses by vaccination. Investigating antibodies with cross clade reactivity is particularly important as these antibodies may target conserved epitopes on the HIV envelope gp160 protein. To this end we have used a clade B YU-2 gp140 trimeric antigen and single-cell antibody cloning methods to obtain 189 new anti-gp140 antibodies representing 51 independent B cell clones from the IgG memory B cells of 3 patients infected with HIV-1 clade A or B viruses and exhibiting broad neutralizing serologic activity. Our results support previous findings showing a diverse antibody response to HIV gp140 envelope protein, characterized by differentially expanded B-cell clones producing highly hypermutated antibodies with heterogenous gp140-specificity and neutralizing activity. In addition to their high-affinity binding to the HIV spike, the vast majority of the new anti-gp140 antibodies are also polyreactive. Although none of the new antibodies are as broad or potent as VRC01 or PG9, two clonally-related antibodies isolated from a clade A HIV-1 infected donor, directed against the gp120 variable loop 3, rank in the top 5% of the neutralizers identified in our large collection of 185 unique gp140-specific antibodies in terms of breadth and potency

The Breadth, but Not the Magnitude, of Circulating Memory B Cell Responses to P. falciparum Increases with Age/Exposure in an Area of Low Transmission

BACKGROUND: Malaria caused by Plasmodium falciparum remains a major cause of death in sub-Saharan Africa. Immunity against symptoms of malaria requires repeated exposure, suggesting either that the parasite is poorly immunogenic or that the development of effective immune responses to malaria may be impaired. METHODS: We carried out two age-stratified cross-sectional surveys of anti-malarial humoral immune responses in a Gambian village where P. falciparum malaria transmission is low and sporadic. Circulating antibodies and memory B cells (MBC) to four malarial antigens were measured using ELISA and cultured B cell ELISpot. FINDINGS AND CONCLUSIONS: The proportion of individuals with malaria-specific MBC and antibodies, and the average number of antigens recognised by each individual, increased with age but the magnitude of these responses did not. Malaria-specific antibody levels did not correlate with either the prevalence or median number of MBC, indicating that these two assays are measuring different aspects of the humoral immune response. Among those with immunological evidence of malaria exposure (defined as a positive response to at least one malarial antigen either by ELISA or ELISPOT), the median number of malaria-specific MBC was similar to median numbers of diphtheria-specific MBC, suggesting that the circulating memory cell pool for malaria antigens is of similar size to that for other antigens

Intracellular Trafficking of Guanylate-Binding Proteins Is Regulated by Heterodimerization in a Hierarchical Manner

Guanylate-binding proteins (GBPs) belong to the dynamin family of large GTPases and represent the major IFN-γ-induced proteins. Here we systematically investigated the mechanisms regulating the subcellular localization of GBPs. Three GBPs (GBP-1, GBP-2 and GBP-5) carry a C-terminal CaaX-prenylation signal, which is typical for small GTPases of the Ras family, and increases the membrane affinity of proteins. In this study, we demonstrated that GBP-1, GBP-2 and GBP-5 are prenylated in vivo and that prenylation is required for the membrane association of GBP-1, GBP-2 and GBP-5. Using co-immunoprecipitation, yeast-two-hybrid analysis and fluorescence complementation assays, we showed for the first time that GBPs are able to homodimerize in vivo and that the membrane association of GBPs is regulated by dimerization similarly to dynamin. Interestingly, GBPs could also heterodimerize. This resulted in hierarchical positioning effects on the intracellular localization of the proteins. Specifically, GBP-1 recruited GBP-5 and GBP-2 into its own cellular compartment and GBP-5 repositioned GBP-2. In addition, GBP-1, GBP-2 and GBP-5 were able to redirect non-prenylated GBPs to their compartment in a prenylation-dependent manner. Overall, these findings prove in vivo the ability of GBPs to dimerize, indicate that heterodimerization regulates sub-cellular localization of GBPs and underscore putative membrane-associated functions of this family of proteins

Diverse Roles and Interactions of the SWI/SNF Chromatin Remodeling Complex Revealed Using Global Approaches

A systems understanding of nuclear organization and events is critical for determining how cells divide, differentiate, and respond to stimuli and for identifying the causes of diseases. Chromatin remodeling complexes such as SWI/SNF have been implicated in a wide variety of cellular processes including gene expression, nuclear organization, centromere function, and chromosomal stability, and mutations in SWI/SNF components have been linked to several types of cancer. To better understand the biological processes in which chromatin remodeling proteins participate, we globally mapped binding regions for several components of the SWI/SNF complex throughout the human genome using ChIP-Seq. SWI/SNF components were found to lie near regulatory elements integral to transcription (e.g. 5′ ends, RNA Polymerases II and III, and enhancers) as well as regions critical for chromosome organization (e.g. CTCF, lamins, and DNA replication origins). Interestingly we also find that certain configurations of SWI/SNF subunits are associated with transcripts that have higher levels of expression, whereas other configurations of SWI/SNF factors are associated with transcripts that have lower levels of expression. To further elucidate the association of SWI/SNF subunits with each other as well as with other nuclear proteins, we also analyzed SWI/SNF immunoprecipitated complexes by mass spectrometry. Individual SWI/SNF factors are associated with their own family members, as well as with cellular constituents such as nuclear matrix proteins, key transcription factors, and centromere components, implying a ubiquitous role in gene regulation and nuclear function. We find an overrepresentation of both SWI/SNF-associated regions and proteins in cell cycle and chromosome organization. Taken together the results from our ChIP and immunoprecipitation experiments suggest that SWI/SNF facilitates gene regulation and genome function more broadly and through a greater diversity of interactions than previously appreciated

Conformational control of the binding of diatomic gases to cytochrome c′

The cytochromes c′ (CYTcp) are found in denitrifying, methanotrophic and photosynthetic bacteria. These proteins are able to form stable adducts with CO and NO but not with O2. The binding of NO to CYTcp currently provides the best structural model for the NO activation mechanism of soluble guanylate cyclase. Ligand binding in CYTcps has been shown to be highly dependent on residues in both the proximal and distal heme pockets. Group 1 CYTcps typically have a phenylalanine residue positioned close to the distal face of heme, while for group 2, this residue is typically leucine. We have structurally, spectroscopically and kinetically characterised the CYTcp from Shewanella frigidimarina (SFCP), a protein that has a distal phenylalanine residue and a lysine in the proximal pocket in place of the more common arginine. Each monomer of the SFCP dimer folds as a 4-alpha-helical bundle in a similar manner to CYTcps previously characterised. SFCP exhibits biphasic binding kinetics for both NO and CO as a result of the high level of steric hindrance from the aromatic side chain of residue Phe 16. The binding of distal ligands is thus controlled by the conformation of the phenylalanine ring. Only a proximal 5-coordinate NO adduct, confirmed by structural data, is observed with no detectable hexacoordinate distal NO adduct