1,503 research outputs found

    Surface-wave-enabled darkfield aperture for background suppression during weak signal detection

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    Sensitive optical signal detection can often be confounded by the presence of a significant background, and, as such, predetection background suppression is substantively important for weak signal detection. In this paper, we present a novel optical structure design, termed surface-wave-enabled darkfield aperture (SWEDA), which can be directly incorporated onto optical sensors to accomplish predetection background suppression. This SWEDA structure consists of a central hole and a set of groove pattern that channels incident light to the central hole via surface plasmon wave and surface-scattered wave coupling. We show that the surface wave component can mutually cancel the direct transmission component, resulting in near-zero net transmission under uniform normal incidence illumination. Here, we report the implementation of two SWEDA structures. The first structure, circular-groove-based SWEDA, is able to provide polarization-independent suppression of uniform illumination with a suppression factor of 1230. The second structure, linear-groove-based SWEDA, is able to provide a suppression factor of 5080 for transverse-magnetic wave and can serve as a highly compact (5.5 micrometer length) polarization sensor (the measured transmission ratio of two orthogonal polarizations is 6100). Because the exact destructive interference balance is highly delicate and can be easily disrupted by the nonuniformity of the localized light field or light field deviation from normal incidence, the SWEDA can therefore be used to suppress a bright background and allow for sensitive darkfield sensing and imaging (observed image contrast enhancement of 27 dB for the first SWEDA)

    Biodiversiteit onder glas : Voedsel voor luizenbestrijders

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    In het praktijknetwerk biodiversiteit onder glas is door glastuinders geëxperimenteerd met bloemen in en rond de kas . Al dan niet in combinatie met bankerplanten zoals granen. Deze brochure is gemaakt om kennis over bloemen en biologische bestrijders te geven en specifiek het nut van biodiversiteit . Biodiversiteit geeft ondersteuning aan meerdere natuurlijke bestrijders van bladluizen. Vooral in de paprikateelt vormen bladluizen soms een ware plaag. Het praktijknetwerk heeft kennis opgeleverd die helpt het agro-eco systeem te versterken

    A probabilistic analysis of the multiknapsack value function

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    The optimal solution value of the multiknapsack problem as a function of the knapsack capacities is studied under the assumption that the profit and weight coefficients are generated by an appropriate random mechanism. A strong asymptotic characterization is obtained, that yiclds a closed form expression for certain special cases

    Evaluation of a follow-up programme after curative resection for colorectal cancer

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    Frequent liver imaging can detect liver metastases from colorectal cancer at an asymptomatic stage. © 1999 Cancer Research Campaig

    Analyzing and Implementing a Feature Mapping Approach to CAD System Interoperability

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    Interoperable information exchange between computer-aided design (CAD) systems is one of the major problems to enable information integration in a collaborative engineering environment. Although a significant amount of work has been done on the extension and standardization of CAD data formats as well as the cooperation of CAD systems in both academy and industry, these approaches are generally low-level and narrowly targeted. Lack of fundamental study of interoperability and generic solution to this problem is the major issue. Our intention of this research is to design a solution of CAD feature interoperability as generic as possible based on a theoretical foundation of language types. In this paper, we present a fundamental model of semantic features and feature mapping process based on the type theory. We implement and demonstrate our approach for automated feature exchange between commercial CAD systems

    Shape optimisation of a snowboard binding highback. A case study of generative design process comparison

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    FEA software is traditionally expensive to purchase, takes a high level of technical skill and understanding and requires users to dedicate years to develop specialist skills. With the increasing popularity of more user-friendly, elementary software packages such as Fusion360, more cost effective and efficient processes can be developed and harnessed, especially by SME’s and designers that don’t have the ability to purchase expensive software packages. One particular FEA element that has recently begun transitioning from highly specialised to more readily available is ‘generative design’ and ‘shape optimisation.' Shape optimisation has only been able to be utilised by large corporations with large research and development budgets. This case study looks at exploring and optimising the methods involved in generative design for product development and it’s aimed at facilitating practises for small to medium enterprises (SME’s).The work described in this paper presents a study using a snowboard binding highback component which was reverse engineered using 3D scanning. A blank model, free of any discerning features was created from the scan and then used as the platform for the generative design phase. This process was completed using easily accessible software (Fusion 360) as well as high-end professional software (Ansys 16). A comparison between the two workflows analyses the resultant model outcomes and outlines efficiencies regarding processing time, technical skill, and latent difficulties of the entry-level process for generative design of the snowboarding high back.This paper aims to demonstrate and describe an optimisation model for generative design and shape optimisation during entry-level product development

    CD4+ T-cell responses to Epstein-Barr virus (EBV) latent-cycle antigens and the recognition of EBV-transformed lymphoblastoid cell lines

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    There is considerable interest in the potential of Epstein-Barr virus (EBV) latent antigen-specific CD4+^+ T cells to act as direct effectors controlling EBV-induced B lymphoproliferations. Such activity would require direct CD4+^+ T-cell recognition of latently infected cells through epitopes derived from endogenously expressed viral proteins and presented on the target cell surface in association with HLA class II molecules. It is therefore important to know how often these conditions are met. Here we provide CD4+^+ epitope maps for four EBV nuclear antigens, EBNA1, -2, -3A, and -3C, and establish CD4+^+ T-cell clones against 12 representative epitopes. For each epitope we identify the relevant HLA class II restricting allele and determine the efficiency with which epitope-specific effectors recognize the autologous EBV-transformed B-lymphoblastoid cell line (LCL). The level of recognition measured by gamma interferon release was consistent among clones to the same epitope but varied between epitopes, with values ranging from 0 to 35% of the maximum seen against the epitope peptide-loaded LCL. These epitope-specific differences, also apparent in short-term cytotoxicity and longer-term outgrowth assays on LCL targets, did not relate to the identity of the source antigen and could not be explained by the different functional avidities of the CD4+^+ clones; rather, they appeared to reflect different levels of epitope display at the LCL surface. Thus, while CD4+^+ T-cell responses are detectable against many epitopes in EBV latent proteins, only a minority of these responses are likely to have therapeutic potential as effectors directly recognizing latently infected target cells

    The effects of age on associations between markers of HIV progression and markers of metabolic function including albumin, haemoglobin and lipid concentrations.

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    OBJECTIVES: We investigated whether age modified associations between markers of HIV progression, CD4 T lymphocyte count and HIV RNA viral load (VL), and the following markers of metabolic function: albumin, haemoglobin, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC). METHODS: A retrospective analysis of data from the United Kingdom Collaborative HIV Cohort was carried out. Analyses were limited to antiretroviral-naïve subjects to focus on the impact of HIV disease itself. A total of 16670 subjects were included in the analysis. Multilevel linear regression models assessed associations between CD4 count/VL and each of the outcomes. Statistical tests for interactions assessed whether associations differed among age groups. RESULTS: After adjustment for gender and ethnicity, there was evidence that lower CD4 count and higher VL were associated with lower TC, LDL-C, haemoglobin and albumin concentrations but higher triglyceride concentrations. Age modified associations between CD4 count and albumin (P 50 years, a 50 cells/μL lower CD4 count correlated with a 2.4 [95% confidence interval (CI) 1.7-3.0], 3.6 (95% CI 3.2-4.0) and 5.1 (95% CI 4.0-6.1) g/L lower haemoglobin concentration and a 0.09 (95% CI 0.07-0.11), 0.12 (95% CI 0.11-0.13) and 0.16 (95% CI 0.13-0.19) g/L lower albumin concentration, respectively. CONCLUSIONS: We present evidence that age modifies associations between CD4 count and plasma albumin and haemoglobin levels. A given reduction in CD4 count was associated with a greater reduction in haemoglobin and albumin concentrations among older people living with HIV. These findings increase our understanding of how the metabolic impact of HIV is influenced by age

    Reconstitution of immunity to adenovirus (Ad) after pediatric bone marrow transplant

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