Very high energy gamma rays from isolated pulsars and non-pulsating objects

This thesis is concerned with the detection of very high energy 7-rays from isolated pulsars and objects that are not known to emit pulsed radiation, using the atmospheric Cerenkov technique. The first chapter summarises the processes by which celestial 7-rays can be generated and absorbed. A discussion of the criteria for selecting objects for study is given. The second chapter describes the atmospheric Cerenkov technique and gives a brief outline of its historical development. Details of the design and operation of the current Durham university V.H.E. 7- ray telescopes are given. The third chapter describes the standard analysis techniques used to search for pulsed and unpulsed emission. The fourth chapter presents results of new observations of four isolated pulsars. Upper limits to the V.H.E. 7-ray flux are derived for each pulsar. A summary of the results is given and conclusions drawn regarding the consequences of the observations for the most popular pulsar model. The fifth chapter deals with new analysis techniques that have been developed to test data for the presence of a signal which is not necessarily periodic. A number of different approaches is described. The results of these techniques when applied to simulated data are presented and conclusions are drawn regarding the relative effectiveness of the tests. The sixth chapter applies the most successful test to data from three objects. Upper limits to the flux from Centaurus A and SN1987aare derived from our observations. Evidence for V.H.E. 7-ray emission from Scorpius X-1 is presented, together with evidence that this emission is modulated with the period of the binary orbit of this system. The final chapter summarises the preceding results and conclusions and indicates areas where current research may lead to substantial improvements in telescope design and analysis techniques

Managing Leadership in University Reform: data-led decision-making, the cost of learning and deja vu?

The contemporary English policy discourse in higher education of ‘Putting Students at the Heart of the System’ has led to an increasing use of managing by performance ‘smart-data’ reinforcing a consumer-led representation of students as ‘partners’ in the ‘business of learning’ within the academy. This approach disguises ongoing fundamental changes to academic work by mixing an increased ‘market-driven’ transparency with ‘accountability’ in ‘institutional and organization management’, utilizing so-called research-led or evidence-informed practice. The policy discourse masks and limits any critique of such data production, or more particularly its purposes and uses, while perhaps yet more significantly, generating an associated ‘modernizing’ rhetoric impacting multiple levels of decision-making throughout the HE institution. Evidence from previous research into school sector reform as data-based decision-making became mainstreamed is used to support our prognosis for the future. Drawing upon documentary analysis of KIS (Key Information Sets) and other publicly available data, this article presents a critique of widespread institutional reform that is rapidly becoming reliant upon what we call ‘data-smart policy’. In conclusion, a series of emerging issues are identified as part of managing the way forward in meeting data access requirements, ensuring student satisfaction and consumer protection, while preserving intellectual values associated with substantive scholarship and sound academic leadership

‘Why has my world become more confusing than it used to be?’ Professional doctoral students reflect on the development of their identity

This article reports on research into the experience of professional doctoral students and is written by the students themselves. We, the authors, are currently studying for the Doctorate in Education at the University of Manchester, UK. We place our work in the context of recent empirical research into the development of doctoral student identity, noting that these literatures are usually authored by programme directors and supervisors. Using a theoretical approach based on the work of Etienne Wenger, we examine how the aims and curriculum of our programme interplay with our professional learning. In interviews with our cohort of students, we explore the complexity and non-linearity of learning. We do not find a simple progression from practitioner to researcher; rather, we find a fluid and complex relationship between those two identities. We consider the extent to which Wenger’s modes of identification are a useful conceptual tool for understanding this interplay and for theorising about our findings. We conclude that there is further scope for the development of our theoretical framework by drawing on other scholarly work on identity development and reflexivit

A response to the House of Commons Education Committee report on Multi-Academy Trusts

The number of schools joining multi-academy trusts has grown over the last five years, and it is expected that this growth will continue. The House of Commons Education Committee has, as a result, looked into the performance and role of these trusts. Steven J Courtney, Ruth McGinity, Steven Jones, Robert Hindle, Stephen M Rayner and Belinda Hughes focus on four key aspects of the Committee’s report and argue that broader questions about the government’s policy remain untouched

National Health Service healthcare staff experience and practices regarding complementary and alternative medicine: an online survey.

The use of complementary and alternative medicine (CAM) is increasing. The most common reported reason for CAM use is dissatisfaction with conventional healthcare. Several studies have reported factors influencing CAM usage and beliefs in the general public but the beliefs of healthcare staff are less well known. This paper reports the results of an online survey of 537 healthcare staff. Our study demonstrated an increased rate of patient referral for CAM from both personal CAM users and those trained in CAM. There was a high level of optimism amongst respondents as to the role CAM may play in patient care with mental health, depression and palliative care cited as the areas with highest expected benefit. Doctors were generally less optimistic about the likelihood of benefit compared to other healthcare staff. Implications for clinical practice, future research and staff education are discussed

Confirming nasogastric tube position with electromagnetic tracking versus pH or X-ray and tube radio-opacity

Recent evidence suggests official statistics greatly underestimate the occurrence of complications from misplaced nasogastric (NG) tubes, even when detected. Current methods of confirming tube position do not provide adequate protection from misplacement. In addition, some tubes are inadequately radio-opaque. We prospectively audited placement of Cortrak polyurethane tubes (PUTs) to determine: accuracy of the electromagnetic (EM) trace in confirming tube position, radio-opacity of PUTs compared with previously placed polyvinylchloride (PVC) Ryles tubes and whether 12 French PUTs can be used to aspirate gastric residual volumes (GRVs). A total of 127 PUTs were placed in 113 patients. EM traces accurately confirmed tube position compared with X-ray (100% agreement). A 'gastric' EM trace has been defined for future use by other operators. PUTs were adequately radio-opaque with good agreement between interpreters (>98%) whereas PVC Ryles tubes were insufficiently radio-opaque (57-73%), invisible in 23% of cases and with poor agreement between interpreters leaving risk of error. The alternative of using pH confirmation was not possible in 44%. In these cases subsequent X-ray incurred a 2-hour delay to feed and medicines. In addition, neither post-placement pH testing nor X-ray warn of lung placement and potential trauma, whereas the EM trace warned of lung placement prior to damage in 7% of placements. 12 French, single-port PUTs appear adequate to aspirate large GRVs. EM tracing may be considered a standalone method of confirming NG tube position. Corflo (Cortrak) PUTs are adequately radio-opaque. Use of PVC Ryles and other inadequately radio-opaque tubes should stop

Profiling invasive Plasmodium falciparum merozoites using an integrated omics approach

The symptoms of malaria are brought about by blood-stage parasites, which are established when merozoites invade human erythrocytes. Our understanding of the molecular events that underpin erythrocyte invasion remains hampered by the short-period of time that merozoites are invasive. To address this challenge, a Plasmodium falciparum gamma-irradiated long-lived merozoite (LLM) line was developed and investigated. Purified LLMs invaded erythrocytes by an increase of 10–300 fold compared to wild-type (WT) merozoites. Using an integrated omics approach, we investigated the basis for the phenotypic difference. Only a few single nucleotide polymorphisms within the P. falciparum genome were identified and only marginal differences were observed in the merozoite transcriptomes. By contrast, using label-free quantitative mass-spectrometry, a significant change in protein abundance was noted, of which 200 were proteins of unknown function. We determined the relative molar abundance of over 1100 proteins in LLMs and further characterized the major merozoite surface protein complex. A unique processed MSP1 intermediate was identified in LLM but not observed in WT suggesting that delayed processing may be important for the observed phenotype. This integrated approach has demonstrated the significant role of the merozoite proteome during erythrocyte invasion, while identifying numerous unknown proteins likely to be involved in invasion

The Solution Structures of Two Human IgG1 Antibodies Show Conformational Stability and Accommodate Their C1q and FcγR Ligands.

The human IgG1 antibody subclass shows distinct properties compared with the IgG2, IgG3, and IgG4 subclasses and is the most exploited subclass in therapeutic antibodies. It is the most abundant subclass, has a half-life as long as that of IgG2 and IgG4, binds the FcγR receptor, and activates complement. There is limited structural information on full-length human IgG1 because of the challenges of crystallization. To rectify this, we have studied the solution structures of two human IgG1 6a and 19a monoclonal antibodies in different buffers at different temperatures. Analytical ultracentrifugation showed that both antibodies were predominantly monomeric, with sedimentation coefficients s20,w (0) of 6.3-6.4 S. Only a minor dimer peak was observed, and the amount was not dependent on buffer conditions. Solution scattering showed that the x-ray radius of gyration Rg increased with salt concentration, whereas the neutron Rg values remained unchanged with temperature. The x-ray and neutron distance distribution curves P(r) revealed two peaks, M1 and M2, whose positions were unchanged in different buffers to indicate conformational stability. Constrained atomistic scattering modeling revealed predominantly asymmetric solution structures for both antibodies with extended hinge structures. Both structures were similar to the only known crystal structure of full-length human IgG1. The Fab conformations in both structures were suitably positioned to permit the Fc region to bind readily to its FcγR and C1q ligands without steric clashes, unlike human IgG4. Our molecular models for human IgG1 explain its immune activities, and we discuss its stability and function for therapeutic applications