Ambiguous words: Post-lapsarian language in Paradise Lost

This article considers the differences between fallen and unfallen language in Paradise Lost. The poem presents divine language as perfect, intuitive and possessing a direct correlation between word and thing. The Falls of both Satan and mankind break that correlation, introducing multivalency, and the ability to dissimilate, into language. Satan rebels, in part, by emphasizing the open-ness of language in a series of puns and contestations over the proper naming of things. Conversely, although Adam and Eve both pun after the Fall, this is done almost unconsciously as a mark of, rather than exultation in, the Fall. Paradise Lost, too, is enmeshed in this fallen language; I argue that it self-consciously deploys the features of postlapsarian language (puns, ambiguity, multivalency) in order to express the limits of its own expression, pointing to its own failure to reproduce sacred song. In Paradise Lost, the glorious achievement is not in overcoming this multivalence, but in expressing it at all. In doing so, it invites its fit audience to recognize the limits of their own language and understanding, and find in those very limits a renewed desire to strive towards the unattainable perfection that the poem seeks to fleetingly capture

Discreteness of Conductance Change in Black Lipid Films

The mechanisms by which inorganic ions cross biological membranes are still effectively unknown. However, it has become very clear during the past few years that the proteins or other macromolecules in the membrane are much more likely to be involved in this process than are the lipids. Thus, experiments with artificial lipid membranes have revealed no indicatfon of the necessary ion transfer or ion selectivity properties among the naturally occurring lipids, whereas many small macromolecules, including some polypeptides, are known to be entirely adequate in these respects

Discreteness of Conductance Change in Black Lipid Films

The mechanisms by which inorganic ions cross biological membranes are still effectively unknown. However, it has become very clear during the past few years that the proteins or other macromolecules in the membrane are much more likely to be involved in this process than are the lipids. Thus, experiments with artificial lipid membranes have revealed no indicatfon of the necessary ion transfer or ion selectivity properties among the naturally occurring lipids, whereas many small macromolecules, including some polypeptides, are known to be entirely adequate in these respects

The impact of host species and vector control measures on the fitness of African malaria vectors

Many malaria vector mosquitoes in Africa have an extreme preference for feeding on humans. This specialization allows them to sustain much higher levels of transmission than elsewhere, but there is little understanding of the evolutionary forces that drive this behaviour. In Tanzania, we used a semi-field system to test whether the well-documented preferences of the vectors An. arabiensis and An. gambiae s.s. for cattle and humans respectively are predicted by the fitness they obtain from host-seeking on these species relative to other available hosts. Mosquito fitness was contrasted when humans were fully exposed, and when they were protected by a typical bednet. The fitness of both vectors varied between host species. The predicted relationship between host preference and fitness was confirmed in An. arabiensis, but not in An. gambiae s.s. whose fitness was similar on humans and other mammals. Use of typical, imperfect bednets generated only minor reductions in An. gambiae s.s. feeding success and fitness on humans, but was predicted to generate a significant reduction in the lifetime reproductive success of An. arabiensis on human relative to cows. This supports the hypothesis that such human-protective measures could additionally benefit malaria control by increasing selection for zoophily in vectors

The impact of mutation and gene conversion on the local diversification of antigen genes in African trypanosomes

Patterns of genetic diversity in parasite antigen gene families hold important information about their potential to generate antigenic variation within and between hosts. The evolution of such gene families is typically driven by gene duplication, followed by point mutation and gene conversion. There is great interest in estimating the rates of these processes from molecular sequences for understanding the evolution of the pathogen and its significance for infection processes. In this study, a series of models are constructed to investigate hypotheses about the nucleotide diversity patterns between closely related gene sequences from the antigen gene archive of the African trypanosome, the protozoan parasite causative of human sleeping sickness in Equatorial Africa. We use a hidden Markov model approach to identify two scales of diversification: clustering of sequence mismatches, a putative indicator of gene conversion events with other lower-identity donor genes in the archive, and at a sparser scale, isolated mismatches, likely arising from independent point mutations. In addition to quantifying the respective probabilities of occurrence of these two processes, our approach yields estimates for the gene conversion tract length distribution and the average diversity contributed locally by conversion events. Model fitting is conducted using a Bayesian framework. We find that diversifying gene conversion events with lower-identity partners occur at least five times less frequently than point mutations on variant surface glycoprotein (VSG) pairs, and the average imported conversion tract is between 14 and 25 nucleotides long. However, because of the high diversity introduced by gene conversion, the two processes have almost equal impact on the per-nucleotide rate of sequence diversification between VSG subfamily members. We are able to disentangle the most likely locations of point mutations and conversions on each aligned gene pair

Failure of vaccination to prevent outbreaks of foot-and-mouth disease

Outbreaks of foot-and-mouth disease persist in dairy cattle herds in Saudi Arabia despite revaccination at intervals of 4-6 months. Vaccine trials provide data on antibody responses following vaccination. Using this information we developed a mathematical model of the decay of protective antibodies with which we estimated the fraction of susceptible animals at a given time after vaccination. The model describes the data well, suggesting over 95% take with an antibody half-life of 43 days. Farm records provided data on the time course of five outbreaks. We applied a 'SLIR' epidemiological model to these data, fitting a single parameter representing disease transmission rate. The analysis provides estimates of the basic reproduction number R(0), which may exceed 70 in some cases. We conclude that the critical intervaccination interval which would provide herd immunity against FMDV is unrealistically short, especially for heterologous challenge. We suggest that it may not be possible to prevent foot-and-mouth disease outbreaks on these farms using currently available vaccines

Genetic and antigenic characterisation of serotype A FMD viruses from East Africa to select new vaccine strains

Vaccine strain selection for emerging foot-and-mouth disease virus (FMDV) outbreaks in enzootic countries can be addressed through antigenic and genetic characterisation of recently circulating viruses. A total of 56 serotype A FMDVs isolated between 1998 and 2012, from Central, East and North African countries were characterised antigenically by virus neutralisation test using antisera to three existing and four candidate vaccine strains and, genetically by characterising the full capsid sequence data. A Bayesian analysis of the capsid sequence data revealed the viruses to be of either African or Asian topotypes with subdivision of the African topotype viruses into four genotypes (Genotypes I, II, IV and VII). The existing vaccine strains were found to be least cross-reactive (good matches observed for only 5.4–46.4% of the sampled viruses). Three bovine antisera, raised against A-EA-2007, A-EA-1981 and A-EA-1984 viruses, exhibited broad cross-neutralisation, towards more than 85% of the circulating viruses. Of the three vaccines, A-EA-2007 was the best showing more than 90% in-vitro cross-protection, as well as being the most recent amongst the vaccine strains used in this study. It therefore appears antigenically suitable as a vaccine strain to be used in the region in FMD control programmes

Paradise Lost and the Politics of the Corporation

This essay considers the effects of corporate activity on the life and work of John Milton. It analyses the ways in which the moral certainties of Paradise Lost are expressed through mercantile metaphors, especially the corporate idea of debt and credit. It further argues that Milton considers virtue through the manner of collective organisation – to be part of an equitable collective is to be virtuous (and vice versa). He therefore turns to the language of the body corporate in Paradise Lost when describing angelic society: this heavenly corporation is the fulfilment of Milton’s ideas of civic virtue, a modulation of his disappointment with the republic in England into an idealised collective