Increasing throughput in IEEE 802.11 by optimal selection of backoff parameters

Engineering and Physical Sciences Research Council. Grant Number: EP/G012628/

Ethnic Diversity, Christian Hegemony and the Emergence of Multi-faith Religious Education in the 1970s

publication-status: PublishedThis is an Author's Original Manuscript of an article whose final and definitive form, the Version of Record, has been published in History of Education, October 2011. Available online at: http://www.tandfonline.com/ or DOI: 10.1080/0046760X.2011.620013This article provides a detailed reconstruction of the processes leading to the formation of the widely influential Birmingham Agreed Syllabus of Religious Instruction (1975). This is contextualised within one of the most significant periods in the history of race relations in the United Kingdom. The authors discuss how this syllabus, and other landmark reforms in religious education (RE) in English schools from the late 1960s, responded to ethnic diversity by promoting supposedly culturally pluralist, multi-faith approaches to RE, which were subsequently perceived as eroding the Christian foundations of British/English national identity. They argue that the vilification of these curriculum reforms by culturally conservative critics was in fact based on an erroneous assessment of the extent to which these renounced the Christian hegemony of RE. They also critique the assumption that the religious clauses of the 1988 Education Reform Act represented a simple transition from culturally pluralist to assimilationist policies for the subject

Coring method of sampling potato tubers to detect ralstonia solanacearum.

Bacterial wilt caused by Ralstonia solanacearum is considered among the most damaging diseases of potato in Sub-Saharan Africa. In Kenya, majority of farmers visually select and save seed from harvested potato tubers and reuse the same tubers for several seasons. Latently infected seed tubers which cannot be identified by visual inspection during certification further compounds the situation compelling the need for laboratory testing. The study evaluated the effectiveness of coring tuber samples to improve sampling efficiency for onward laboratory diagnosis. In this study, the coring method of sampling potato tubers for detection R. solanacearum was evaluated. Coring involves taking multiple tuber samples direct from the stolon attachment site into a collection tube containing extraction buffer that provides the extract for further diagnostic tests. Coring was assessed using field samples from different potato growing regions of Kenya including, Koibatek, Molo, Uasin Gishu, Bungoma and Kisii and tested using Nitrocellulose Membrane (NCM) ELISA. These results were compared to PCR, qPCR and LAMP. Coring method was statistically reliable (p>0.05) when compared to the standard sampling method used in Kenya to detect R. solanacearum. The coring of potato tubers is a reliable and quicker method of sampling that reduces the turnaround time of testing hence improving efficiency

A utility based framework for optimal network measurement

Packet level measurement is now routinely used to evaluate the loss and delay performance of broadband networks. In active measurement, probe packets provide samples of the loss and delay and from these samples the performance of the traffic as a whole can be deduced. However this is prone to errors: inaccuracy due to taking insufficient samples, self-interference due to injecting too many probe packets, and possible sample-correlation induced bias. In this paper we consider the optimisation of probing rate by treating all measurements as numerical experiments which can be optimally designed by using the statistical principles of design of experiments. We develop an analytical technique that quantifies an overall utility function associated with: (i) the disruption caused per probe packet, (ii) the bias and (iii) the variance as a function of the probing (sampling) rate. Our numerical results show that the optimal probing rate depends strongly on what parameter the network engineer seeks to measure.</p

'Does the design of settings where acute care is delivered meet the needs of older people? Perspectives of patients, family carers, and staff

Background: Older people with an acute illness, many of whom are also frail, form a significant proportion of the acute hospital inpatient population. Attention is focusing on ways of improving the physical environment to optimize health outcomes and staff efficiency. Purpose: This paper explores the effects of the physical environment in three acute care settings: Acute Hospital Site, In-patient Rehabilitation Hospital, and Intermediate Care Provision (a nursing home with some beds dedicated to intermediate care) chosen to represent different steps on the acute care pathway for older people and gain the perspectives of patients, family carers and staff. Methods: Semi structured interviews were undertaken with 40 patient/carer dyads (where available) and three staff focus groups were conducted in each care setting with a range of staff. Results: Multiple aspects of the physical environment were reported as important by patients, family carers, and staff. For example, visitors stressed the importance of access and parking; patients valued environments where privacy and dignity were protected; storage space was poor across all sites; security was important to patients but visitors want easy access to wards. Conclusions: The physical environment is a significant component of acute care for older people, many of whom are also frail, but often comes second to organization of care, or relationships between actors in an episode of care

Tackling Ageing Continence through Theory, Tools & Technology

Originally presented at ‘Aging and Society: An Interdisciplinary Conference’, University of California, Berkeley (2011), this article was double-blind peer reviewed, receiving scores of 96% and 73%. It outlines the interdisciplinary research of the cross-Research-Council-funded New Dynamics of Ageing Tackling Ageing Continence through Theory Tools & Technology (TACT3) project (2008–12), which brought together designers, social scientists, bio-engineers, chemists and care-management services to understand the challenges faced by an ageing population in the management of continence. Bichard’s Work Package, ‘Challenging Environmental Barriers to Continence’, explored the need for public toilet provision as essential for quality of life, health and well-being. It developed a life-course methodology that considered ageing from birth through to advanced age (0–101 years), and involved inclusive design research with members of the public and providers of facilities to assess public expectations and provider limitations in service provision. As co-investigator on TACT3, this research built on Bichard’s previous work for the VivaCity2020 consortium (Bichard REF Output 2). Whereas the VivaCity2020 work focused on architectural barriers in toilet provision, the TACT3 project examined the problem in service provision, and how, through inclusive design research, service-design solutions might be explored and implemented. Bichard’s contribution to the TACT3 project produced The Great British Public Toilet Map (http://greatbritishpublictoiletmap.rca.ac.uk/), a public participation website that provides information and locations of public toilets, encouraging members of the public to contact relevant local authorities that have not released information in the format of Open Data. Secondary analysis of TACT3 data for references to issues of personal safety and community initiative in toilet provision was used for the ESRC-funded Robust Accessible Toilets (RATs) project (2011) and produced Publicly Accessible Toilets: An Inclusive Design Guide (2011). Related published conference papers include those in ‘Cumulus 2010’ (China) and ‘Include 2011’ (UK)

O(N) Sigma Model as a Three Dimensional Conformal Field Theory

We study a three dimensional conformal field theory in terms of its partition function on arbitrary curved spaces. The large $N$ limit of the nonlinear sigma model at the non-trivial fixed point is shown to be an example of a conformal field theory, using zeta--function regularization. We compute the critical properties of this model in various spaces of constant curvature ($R^2 \times S^1$, $S^1\times S^1 \times R$, $S^2\times R$, $H^2\times R$, $S^1 \times S^1 \times S^1$ and $S^2 \times S^1$) and we argue that what distinguishes the different cases is not the Riemann curvature but the conformal class of the metric. In the case $H^2\times R$ (constant negative curvature), the $O(N)$ symmetry is spontaneously broken at the critical point. In the case $S^2\times R$ (constant positive curvature) we find that the free energy vanishes, consistent with conformal equivalence of this manifold to $R^3$, although the correlation length is finite. In the zero curvature cases, the correlation length is finite due to finite size effects. These results describe two dimensional quantum phase transitions or three dimensional classical ones.Comment: 35 pages, TeX, (Revised version, to appear in Nucl. Phys. B--paper shortened, a discussion added and other minor corrections

Influence of defects on the electronic and magnetic properties of half-metallic CrAs, CrSe and CrSb zinc-blende compounds

We present an extended study of single impurity atoms and atomic swaps in half-metallic CrAs, CrSb and CrSe zinc-blende compounds. Although the perfect alloys present a rather large gap in the minority-spin band, all defects under study, with the exception of void impurities at Cr and sp sites and Cr impurities at sp sites (as long as no swap occurs), induce new states within the gap. The Fermi level can be pinned within these new minority states depending on the lattice constant used for the calculations and the electronegativity of the sp atoms. Although these impurity states are localized in space around the impurity atoms and very fast we regain the bulk behavior, their interaction can lead to wide bands within the gap and thus loss of the half-metallic character