Self-excision of the BAC sequences from the recombinant Marek's disease virus genome increases replication and pathogenicity

Cloning of full length genomes of herpesviruses as bacterial artificial chromosomes (BAC) has greatly facilitated the manipulation of the genomes of several herpesviruses to identify the pathogenic determinants. We have previously reported the construction of the BAC clone (pRB-1B5) of the highly oncogenic Marek's disease virus (MDV) strain RB-1B, which has proven to be a valuable resource for elucidating several oncogenic determinants. Despite the retention of the BAC replicon within the genome, the reconstituted virus was able to induce tumours in susceptible chickens. Nevertheless, it was unclear whether the presence of the BAC influenced the full oncogenic potential of the reconstituted virus. To maximize the closeness of BAC-derived virus to the parental RB-1B strain, we modified the existing pRB-1B5 clone by restoring the Us2 and by introducing SV40-cre cassette within the loxP sites of the mini-F plasmid, to allow self-excision of the plasmid sequences in chicken cells. The reconstituted virus from the modified clone showed significant improvement in replication in vitro and in vivo. Excision of the BAC sequences also enhanced the pathogenicity to levels similar to that of the parental virus, as the cumulative incidence of Marek's disease in groups infected with the recombinant and the parental viruses showed no significant differences. Thus, we have been able to make significant improvements to the existing BAC clone of this highly oncogenic virus which would certainly increase its usefulness as a valuable tool for studies on identifying the oncogenic determinants of this major avian pathogen

Pathogenicity of a Very Virulent Strain of Marek's Disease Herpesvirus Cloned as Infectious Bacterial Artificial Chromosomes

Bacterial artificial chromosome (BAC) vectors containing the full-length genomes of several herpesviruses have been used widely as tools to enable functional studies of viral genes. Marek's disease viruses (MDVs) are highly oncogenic alphaherpesviruses that induce rapid-onset T-cell lymphomas in chickens. Oncogenic strains of MDV reconstituted from BAC clones have been used to examine the role of viral genes in inducing tumours. Past studies have demonstrated continuous increase in virulence of MDV strains. We have previously reported on the UK isolate C12/130 that showed increased virulence features including lymphoid organ atrophy and enhanced tropism for the central nervous system. Here we report the construction of the BAC clones (pC12/130) of this strain. Chickens were infected with viruses reconstituted from the pC12/130 clones along with the wild-type virus for the comparison of the pathogenic properties. Our studies show that BAC-derived viruses induced disease similar to the wild-type virus, though there were differences in the levels of pathogenicity between individual viruses. Generation of BAC clones that differ in the potential to induce cytolytic disease provide the opportunity to identify the molecular determinants of increased virulence by direct sequence analysis as well as by using reverse genetics approaches on the infectious BAC clones

Measuring discomfort from glare: recommendations for good practice

This article presents a review of the methods used for subjective evaluation of discomfort from glare, focusing on the two procedures most frequently used in past research – adjustment and category rating. Evidence is presented to demonstrate that some aspects of these procedures influence the evaluation, such as the range of glare source luminances available in an adjustment procedure, leading to biased evaluations and which hence reduce the reliability and validity of the data. The article offers recommendations for good practice when using these procedures and also suggests alternative methods that might be explored in further work

Different expressions of the same mode: a recent dialogue between archaeological and contemporary drawing practices

In this article we explore what we perceive as pertinent features of shared experience at the excavations of an Iron Age Hillfort at Bodfari, North Wales, referencing artist, archaeologist and examples of seminal art works and archaeological records resulting through inter-disciplinary collaboration. We explore ways along which archaeological and artistic practices of improvisation become entangled and productive through their different modes of mark-making. We contend that marks and memories of artist and archaeologist alike emerge interactively, through the mutually constituting effects of the object of study, the tools of exploration, and the practitioners themselves, when they are enmeshed in the cross-modally bound activities. These include, but are not limited to, remote sensing, surveying, mattocking, trowelling, drawing, photographing, videoing and sound recording. These marks represent the co-signatories: the gesture of the often anonymous practitioners, the voice of the deposits, as well as the imprint of the tools, and their interplay creates a multi-threaded narrative documenting their modes of intra-action, in short our practices. They occupy the conceptual space of paradata, and in the process of saturating the interstices of digital cognitive prosthetics they lend probity to their translations in both art form and archive

Recognition and social freedom

In this paper I develop an account of social freedom grounded in intersubjective recognition, which I term the “normative authorisation” account. According to this model, a person enjoys social freedom if she is recognised as a discursive equal who can engage in justificatory dialogue with other social agents about the appropriateness of her reasons for action. I contrast this with Axel Honneth’s theory of social freedom, which I label the “self-realisation” account. Within this model, the affirmative recognition of others is required in order to achieve a positive relation-to-self and hence freedom. I highlight several issues with this account, which challenge the relationship Honneth draws between social recognition and freedom. I demonstrate that the normative authorisation account avoids these problems. I also show how it captures some basic features of our everyday, normative interactions. Finally, I suggest that the account fits well with recent work on epistemic injustice. Specifically, it shows that establishing the social conditions of freedom requires ensuring epistemically-just social relations. In sum, the normative authorisation account is an explanatorily powerful, inclusive theory of social freedom that fits well with wider accounts of justice and freedom. It represents the most promising way of construing social freedom in terms of interpersonal recognition

Some cultural consequences in Spain of the Spanish Invasion of Morocco 1859-60

This article argues is a contribution to the study of interrelationships between colonialism, art, and literature in the nineteenth century. The article argues that the Spanish invasion of Morocco in 1859 led to contradictions and tensions within liberal nationalism, not least because of concerns about the tensions between the need for military reassertion of Spain and the respect for the independence of nations. This led to some reconfiguration of Spanish intellectuals' already complex relationship with North Africa and Islam. A major, perhaps surprising consequence of this reconfiguration, was some equation of Moroccan identity with a monotonous surface that was resistant to the gaze. In consequence, the Catalan painter Fortuny's crucial experience of Morocco led him to value near blank surfaces, and thus to make a major contribution to the origins of modern art

A direct comparison of strategies for combinatorial RNA interference

<p>Abstract</p> <p>Background</p> <p>Combinatorial RNA interference (co-RNAi) is a valuable tool for highly effective gene suppression of single and multiple-genes targets, and can be used to prevent the escape of mutation-prone transcripts. There are currently three main approaches used to achieve co-RNAi in animal cells; multiple promoter/shRNA cassettes, long hairpin RNAs (lhRNA) and miRNA-embedded shRNAs, however, the relative effectiveness of each is not known. The current study directly compares the ability of each co-RNAi method to deliver pre-validated siRNA molecules to the same gene targets.</p> <p>Results</p> <p>Double-shRNA expression vectors were generated for each co-RNAi platform and their ability to suppress both single and double-gene reporter targets were compared. The most reliable and effective gene silencing was achieved from the multiple promoter/shRNA approach, as this method induced additive suppression of single-gene targets and equally effective knockdown of double-gene targets. Although both lhRNA and microRNA-embedded strategies provided efficient gene knockdown, suppression levels were inconsistent and activity varied greatly for different siRNAs tested. Furthermore, it appeared that not only the position of siRNAs within these multi-shRNA constructs impacted upon silencing activity, but also local properties of each individual molecule. In addition, it was also found that the insertion of up to five promoter/shRNA cassettes into a single construct did not negatively affect the efficacy of each individual shRNA.</p> <p>Conclusions</p> <p>By directly comparing the ability of shRNAs delivered from different co-RNA platforms to initiate knockdown of the same gene targets, we found that multiple U6/shRNA cassettes offered the most reliable and predictable suppression of both single and multiple-gene targets. These results highlight some important strengths and pitfalls of the currently used methods for multiple shRNA delivery, and provide valuable insights for the design and application of reliable co-RNAi.</p

An experimental study on the effect of visual tasks on discomfort due to peripheral glare

This article concerns discomfort due to sources of glare in the peripheral visual field. A visual task is needed to maintain foveal fixation at a known location and in past studies the tasks have ranged from a simple fixation mark to a task requiring greater cognitive attention such as reading. It was hypothesized that these different approaches to control visual attention would influence the evaluation of discomfort. This article reports an experiment which compared evaluations of discomfort when using the two visual tasks, a simple circle and a pseudo-text reading task, and two procedures, category rating and luminance adjustment. The results from both procedures confirmed the hypothesis: a lower degree of discomfort was expressed in the pseudo-text trials than in trials with the circular fixation mark

Epistemic injustice: A role for recognition?

© The Author(s) 2017. My aim in this article is to propose that an insightful way of articulating the feminist concept of epistemic injustice can be provided by paying significant attention to recognition theory. The article intends to provide an account for diagnosing epistemic injustice as a social pathology and also attempts to paint a picture of some social cure of structural forms of epistemic injustice. While there are many virtues to the literature on epistemic injustice, epistemic exclusion and silencing, current discourse on diagnosing as well as explicating and overcoming these social pathologies can be improved and enriched by bringing recognition theory into the conversation: under recognition theory, social normative standards are constructed out of the moral grammar of recognition attributions. I shall argue that the failure to properly recognize and afford somebody or a social group the epistemic respect they merit is an act of injustice in the sense of depriving individuals of a progressive social environment in which the epistemic respect afforded to them plays a significant role in enabling and fostering their self-confidence as rational enquirers. Testimonial injustice is particularly harrowing, because it robs a group or an individual of the status of a rational enquirer, thereby creating an asymmetrical cognitive environment in which that group or individual is not deemed one’s conversational peer. Hermeneutical injustice is particularly harrowing, because asymmetrical cognitive environments further entrench the normative power of ideology