982 research outputs found

    Further investigation of a contactless patient-electrode interface of an Electrical Impedance Mammography system

    Get PDF
    The Sussex Mk4 Electrical Impedance Mammography (EIM) system is a novel instrument, designed for the detection of early breast cancer, based upon Electrical Impedance Tomography (EIT). Many innovations in the field have been incorporated in the design improving both signal distribution and response. This paper investigates the behaviour of the contactless patient-electrode interface. The interface was studied in detail using phantom and healthy volunteer, in-vivo, data. Our findings show the necessity for the careful design of electrode enclosure so that the response of the system is not affected by the unpredictable positioning of the breast; it closely mimics those conditions seen when using the phantom. The paper includes a number of possible designs and their individual characteristics. In addition an explanation on the unanticipated effects and solutions for such are described. © 2010 IOP Publishing Ltd

    Nasal Lipopolysaccharide Challenge and Cytokine Measurement Reflects Innate Mucosal Immune Responsiveness

    Get PDF
    <div><p>Background</p><p><b>P</b>ractical methods of monitoring innate immune mucosal responsiveness are lacking. Lipopolysaccharide (LPS) is a component of the cell wall of Gram negative bacteria and a potent activator of Toll-like receptor (TLR)-4. To measure LPS responsiveness of the nasal mucosa, we administered LPS as a nasal spray and quantified chemokine and cytokine levels in mucosal lining fluid (MLF).</p><p>Methods</p><p>We performed a 5-way cross-over, single blind, placebo-controlled study in 15 healthy non-atopic subjects (n = 14 <i>per protocol</i>). Doses of ultrapure LPS (1, 10, 30 or 100μg/100μl) or placebo were administered by a single nasal spray to each nostril. Using the recently developed method of nasosorption with synthetic adsorptive matrices (SAM), a series of samples were taken. A panel of seven cytokines/chemokines were measured by multiplex immunoassay in MLF. mRNA for intercellular cell adhesion molecule-1 (ICAM-1) was quantified from nasal epithelial curettage samples taken before and after challenge.</p><p>Results</p><p>Topical nasal LPS was well tolerated, causing no symptoms and no visible changes to the nasal mucosa. LPS induced dose-related increases in MLF levels of IL-1β, IL-6, CXCL8 (IL-8) and CCL3 (MIP-1α) (AUC at 0.5 to 10h, compared to placebo, p<0.05 at 30 and 100μg LPS). At 100μg LPS, IL-10, IFN-α and TNF-α were also increased (p<0.05). Dose-related changes in mucosal ICAM-1 mRNA were also seen after challenge, and neutrophils appeared to peak in MLF at 8h. However, 2 subjects with high baseline cytokine levels showed prominent cytokine and chemokine responses to relatively low LPS doses (10μg and 30μg LPS).</p><p>Conclusions</p><p>Topical nasal LPS causes dose-dependent increases in cytokines, chemokines, mRNA and cells. However, responsiveness can show unpredictable variations, possibly because baseline innate tone is affected by environmental factors. We believe that this new technique will have wide application in the study of the innate immune responses of the respiratory mucosa.</p><p>Key Messages</p><p>Ultrapure LPS was used as innate immune stimulus in a human nasal challenge model, with serial sampling of nasal mucosal lining fluid (MLF) by nasosorption using a synthetic absorptive matrix (SAM), and nasal curettage of mucosal cells. A dose response could be demonstrated in terms of levels of IL-1β, IL-6, CXCL8 and CCL3 in MLF, as well as ICAM-1 mRNA in nasal curettage specimens, and levels of neutrophils in nasal lavage. Depending on higher baseline levels of inflammation, there were occasional magnified innate inflammatory responses to LPS.</p><p>Trial Registration</p><p>Clinical Trials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT02284074?term=nasal+lipopolysaccharide&rank=1" target="_blank">NCT02284074</a></p></div

    Media outlets and their moguls: why concentrated individual or family ownership is bad for editorial independence

    Get PDF
    This article investigates the levels of owner influence in 211 different print and broadcast outlets in 32 different European media markets. Drawing on the literature from industrial organisation, it sets out reasons why we should expect greater levels of influence where ownership of individual outlets is concentrated; where it is concentrated in the hands of individuals or families; and where ownership groups own multiple outlets in the same media market. Conversely, we should expect lower levels of influence where ownership is dispersed between transnational companies. The articles uses original data on the ownership structures of these outlets, and combines it with reliable expert judgments as to the level of owner influence in each of the outlets. These hypotheses are tested and confirmed in a multilevel regression model of owner influence. The findings are relevant for policy on ownership limits in the media, and for the debate over transnational versus local control of media

    A flexible low-cost, high-precision, single interface electrical impedance tomography system for breast cancer detection using FPGA

    Get PDF
    Typically, in multi-frequency Electrical Impedance Tomography (EIT) systems, a current is applied and the voltages developed across the subject are detected. However, due to the complexity of designing stable current sources, there has been mention in the literature of applying a voltage to the subject whilst measuring the consequent current flow. This paper presents a comparative study between the two techniques in a novel design suitable for the detection of breast cancers. The suggested instrument borrows the best features of both the injection of current and the application of voltage, circumventing their limitations. Furthermore, the system has a common patient-electrode interface for both methodologies, whilst the control of the system and the necessary signal processing is carried out in a field programmable gate array (FPGA). Through this novel system, wide-bandwidth, low-noise, as well as high-speed (frame rate) can be achieved

    Using geospatial information to connect ecosystem services and human well-being in Kenya

    Get PDF
    The application of geospatial information in the analysis of ecosystem services would help decision makers to develop programs for poverty reduction in Kenya that would improve the targeting of social expenditures and ecosystem interventions so that they reach areas of greatest need

    Investigating the New Landscapes of Welfare: Housing Policy, Politics and the Emerging Research Agenda

    Get PDF
    As debates about housing form an increasingly important arena of political controversy, much has been written about the new fissures that have appeared as governments not only struggle to reduce public expenditure deficits but also attempt to address problems such as affordability and homelessness. It is widely anticipated that new conflicts will be played out in the private rental market as access to homeownership becomes unrealistic and the supply of social housing diminishes. However, what other tensions might surface; that hitherto have not been subject to the critical gaze of housing research? In this paper, we provide some thoughts on the nascent policy issues as well as the ideological schisms that are likely to develop in coming years, offering suggestions as to how the focus of housing policy research might be reoriented towards a “politics” framework to capture and better understand the conflicts that are likely to arise

    The uses and functions of ageing celebrity war reporters

    Get PDF
    This article starts from the premise that recognition of professional authority and celebrity status depends on the embodiment and performance of field-specific dispositional practices: there’s no such thing as a natural, though we often talk about journalistic instinct as something someone simply has or doesn’t have. Next, we have little control over how we are perceived by peers and publics, and what we think are active positioning or subjectifying practices are in fact, after Bourdieu, revelations of already-determined delegation. The upshot is that two journalists can arrive at diametrically opposed judgements on the basis of observation of the same actions of a colleague, and as individuals we are blithely hypocritical in forming (or reciting) evaluations of the professional identity of celebrities. Nowhere is this starker than in the discourse of age-appropriate behaviour, which this paper addresses using the examples of ‘star’ war reporters John Simpson, Kate Adie and Martin Bell. A certain rough-around-the-edges irreverence is central to dispositional authenticity amongst war correspondents, and for ageing hacks this incorporates gendered attitudes to sex and alcohol as well as indifference to protocol. And yet perceived age-inappropriate sexual behaviour is also used to undermine professional integrity, and the paper ends by outlining the phenomenological context that makes possible this effortless switching between amoral and moralising recognition by peers and audiences alike

    Structural and Genomic Insights Into Pyrazinamide Resistance in Mycobacterium tuberculosis Underlie Differences Between Ancient and Modern Lineages.

    Get PDF
    Resistance to drugs used to treat tuberculosis disease (TB) continues to remain a public health burden, with missense point mutations in the underlying Mycobacterium tuberculosis bacteria described for nearly all anti-TB drugs. The post-genomics era along with advances in computational and structural biology provide opportunities to understand the interrelationships between the genetic basis and the structural consequences of M. tuberculosis mutations linked to drug resistance. Pyrazinamide (PZA) is a crucial first line antibiotic currently used in TB treatment regimens. The mutational promiscuity exhibited by the pncA gene (target for PZA) necessitates computational approaches to investigate the genetic and structural basis for PZA resistance development. We analysed 424 missense point mutations linked to PZA resistance derived from ∼35K M. tuberculosis clinical isolates sourced globally, which comprised the four main M. tuberculosis lineages (Lineage 1-4). Mutations were annotated to reflect their association with PZA resistance. Genomic measures (minor allele frequency and odds ratio), structural features (surface area, residue depth and hydrophobicity) and biophysical effects (change in stability and ligand affinity) of point mutations on pncA protein stability and ligand affinity were assessed. Missense point mutations within pncA were distributed throughout the gene, with the majority (>80%) of mutations with a destabilising effect on protomer stability and on ligand affinity. Active site residues involved in PZA binding were associated with multiple point mutations highlighting mutational diversity due to selection pressures at these functionally important sites. There were weak associations between genomic measures and biophysical effect of mutations. However, mutations associated with PZA resistance showed statistically significant differences between structural features (surface area and residue depth), but not hydrophobicity score for mutational sites. Most interestingly M. tuberculosis lineage 1 (ancient lineage) exhibited a distinct protein stability profile for mutations associated with PZA resistance, compared to modern lineages
    corecore