19,410 research outputs found

    Non-destructive spatial heterodyne imaging of cold atoms

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    We demonstrate a new method for non-destructive imaging of laser-cooled atoms. This spatial heterodyne technique forms a phase image by interfering a strong carrier laser beam with a weak probe beam that passes through the cold atom cloud. The figure of merit equals or exceeds that of phase-contrast imaging, and the technique can be used over a wider range of spatial scales. We show images of a dark spot MOT taken with imaging fluences as low as 61 pJ/cm^2 at a detuning of 11 linewidths, resulting in 0.0004 photons scattered per atom.Comment: text+3 figures, submitted to Optics Letter

    Workforce development and effective evaluation of projects

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    Date of Acceptance: 01/05/2014The success of a project or programme is typically determined in relation to outputs. However, there is a commitment among UK public services to spending public funds efficiently and on activities that provide the greatest benefit to society. Skills for Health recognised the need for a tool to manage the complex process of evaluating project benefits. An integrated evaluation framework was developed to help practitioners identify, describe, measure and evaluate the benefits of workforce development projects. Practitioners tested the framework on projects within three NHS trusts and provided valuable feedback to support its development. The prospective approach taken to identify benefits and collect baseline data to support evaluation was positively received and the clarity and completeness of the framework, as well as the relevance of the questions, were commended. Users reported that the framework was difficult to complete; an online version could be developed, which might help to improve usability. Effective implementation of this approach will depend on the quality and usability of the framework, the willingness of organisations to implement it, and the presence or establishment of an effective change management culture.Peer reviewedFinal Accepted Versio

    Shear Bond Strength Comparison between Two Orthodontic Adhesives and Self-Ligating and Conventional Brackets

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    Objective: To evaluate and compare the shear bond strengths of two adhesives using two types of brackets: a conventional and a self-ligating bracket system. Materials and Methods: Sixty extracted human premolars were collected. The premolars were randomly divided into three groups of 20 teeth. All three groups were direct bonded. Groups 1 and 2 used light-cured adhesive and primer (Transbond XT) with a conventional (Orthos) and a self-ligating bracket (Damon 2), respectively. Group 3 used a light-cured primer (Orthosolo) and a light-cured adhesive (BlΕ«gloo) with a self-ligating bracket (Damon 2). The specimens were stored in distilled water at 37Β°C for 40 Β± 2 hours, after which they were debonded and inspected for Adhesive Remnant Index (ARI) scoring. Results: The mean shear bond strength was 15.2 MPa for group 1, 23.2 MPa for group 2, and 24.8 MPa for group 3. A one-way analysis of variance and post hoc Tukey test showed significant differences in bond strength (P \u3c .001) between group 1 and groups 2 and 3 but no significant difference (P \u3e .05) between groups 2 and 3. A Weibull analysis demonstrated that all three groups provided sufficient bond strength with over 90% survival rate at normal masticatory and orthodontic force levels. A Kruskal-Wallis test showed no significant difference (P \u3e .05) in ARI scores among all three groups. Conclusions: All three groups demonstrated clinically acceptable bond strength. The Damon 2 self-ligating bracket exhibited satisfactory in vitro bond strength with both adhesive systems used

    Odd Parity and Line Nodes in Non-Symmorphic Superconductors

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    Group theory arguments have been invoked to argue that odd parity order parameters cannot have line nodes in the presence of spin-orbit coupling. In this paper we show that these arguments do not hold for certain non-symmorphic superconductors. Specifically, we demonstrate that when the underlying crystal has a twofold screw axis, half of the odd parity representations vanish on the Brillouin zone face perpendicular to this axis. Many unconventional superconductors have non-symmorphic space groups, and we discuss implications for several materials, including UPt3, UBe13, Li2Pt3B and Na4Ir3O8.Comment: 4 page

    Folic acid prescription in pregnancy.

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    We resolved to prescribe folic acid supplements for all women who attended this practice during the first twelve weeks of pregnancy. Six months after this decision a prescription was recorded in only 13% of cases: this compared with 18% during the two months immediately following the decision. It was resolved to improve this performance and observations six months later revealed a prescription recorded in 63% of cases. Subsequently a new form for recording an antenatal consultation was devised and six months after its implementation, 100% recording of folate prescription for appropriate cases was observed. It was concluded that these simple audit exercises prompted changes in practice which helped to improve standards of patient care

    Avian Resistance to Campylobacter jejuni Colonization Is Associated with an Intestinal Immunogene Expression Signature Identified by mRNA Sequencing

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    peer-reviewedThis research was funded by the The Irish Department of Agriculture and Food’s Food Institutional Research Measure (http://www.agriculture.gov.ie/ research/foodinstitutionalresearchmeasurefirm) – Grant No: 06_RDD_486.Campylobacter jejuni is the most common cause of human bacterial gastroenteritis and is associated with several post-infectious manifestations, including onset of the autoimmune neuropathy Guillain-BarrΓ© syndrome, causing significant morbidity and mortality. Poorly-cooked chicken meat is the most frequent source of infection as C. jejuni colonizes the avian intestine in a commensal relationship. However, not all chickens are equally colonized and resistance seems to be genetically determined. We hypothesize that differences in immune response may contribute to variation in colonization levels between susceptible and resistant birds. Using high-throughput sequencing in an avian infection model, we investigate gene expression associated with resistance or susceptibility to colonization of the gastrointestinal tract with C. jejuni and find that gut related immune mechanisms are critical for regulating colonization. Amongst a single population of 300 4-week old chickens, there was clear segregation in levels of C. jejuni colonization 48 hours post-exposure. RNAseq analysis of caecal tissue from 14 C. jejuni-susceptible and 14 C. jejuni-resistant birds generated over 363 million short mRNA sequences which were investigated to identify 219 differentially expressed genes. Significantly higher expression of genes involved in the innate immune response, cytokine signaling, B cell and T cell activation and immunoglobulin production, as well as the renin-angiotensin system was observed in resistant birds, suggesting an early active immune response to C. jejuni. Lower expression of these genes in colonized birds suggests suppression or inhibition of a clearing immune response thus facilitating commensal colonization and generating vectors for zoonotic transmission. This study describes biological processes regulating C. jejuni colonization of the avian intestine and gives insight into the differential immune mechanisms incited in response to commensal bacteria in general within vertebrate populations. The results reported here illustrate how an exaggerated immune response may be elicited in a subset of the population, which alters host-microbe interactions and inhibits the commensal state, therefore having wider relevance with regard to inflammatory and autoimmune disease
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