142 research outputs found

    Determination of azimuth angle, incidence angle, and contact-potential difference for low-energy electron-diffraction fine-structure measurements

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    Low-energy electron-diffraction fine-structure data can often have relatively large inconsistencies associated with the electron-beam incidence conditions. This is in part due to the difficulties associated with working with electrons in the range 0–40 eV and in part due to the crystal being oriented azimuthally before being put in the vacuum system. The angle of incidence is often measured optically, but the optical and electron paths need not coincide if residual magnetic fields are present. We describe a technique for determining the angles of incidence and azimuth from the data themselves. This relies upon two factors: the ability to vary the azimuth angle continuously and the ability to see two sets of fine-structure features on one I-V scan. This technique is applied to fine-structure data obtained from clean Cu(001) and O/Cu(001) surfaces. We hope that the technique described will help give confidence to those collecting such data that these angles can be uniquely determined and that the data can be usefully analyzed. The uncertainty of not having a technique for this purpose has prevented groups from publishing such data in the past

    Mapping innovation in India’s creative industries: an ecosystem framework

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    This paper reports on an ongoing research study funded by UKRI to map India’s creative industries. Using an ecosystem framework, it has focused on strategy/policy; tangible and intangible infrastructure; funding and investment to understand innovation drivers and barriers across nine sub-sector value chains. The research established there is no one creative industries policy.Responsibility is split across 16 government ministries and 28states. Much of India’s economy is informal, with limited data on policy effects. Nevertheless, four important policies are shaping the creative industries landscape, supplemented by investment from global brands into textiles, media and advertising. These are driving innovation and design for social and ecological sustainability. At the time of writing the study is undertaking deep dives into CreaTec, Design for sustainability in fashion and textiles, and emerging geographic concentrations. It has identified a distinctive focus on how supply chains might informUK circular fashion and media production polic

    The Impact of Analyst Forecast Errors on Fundamental Indexation: The Australian Evidence

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    AbstractEvidence from many developed markets suggests that fundamental indices outperform capitalisation-weighted indices. Existing studies suspect a story of market mispricing, yet a mechanism has not been identified. Using Australian data, we study the relation between analyst forecast errors and the performance of various fundamental indices. We find that fundamental indices contain a relatively higher exposure to stocks with low analyst long-term growth forecasts. Valuations for these stocks are ex ante overly pessimistic and drive the statistical significance of alphas produced by fundamental indexation. We show how hedging against analyst forecast errors can generate additional alpha for investors using fundamental indexation.</jats:p

    Glycoproteomic studies of IgE from a novel hyper IgE syndrome linked to PGM3 mutation

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    International audienceGlycans serve as important regulators of antibody activities and half-lives. IgE is the most heavily glycosylated antibody, but in comparison to other antibodies little is known about its glycan structure function relationships. We therefore describe the site specific IgE glycosylation from a patient with a novel hyper IgE syndrome linked to mutations in PGM3, which is an enzyme involved in synthesizing UDP-GlcNAc, a sugar donor widely required for glycosylation. A two-step method was developed to prepare two IgE samples from less than 1 mL of serum collected from a patient with PGM3 mutation and a patient with atopic dermatitis as a control subject. Then, a glycoproteomic strategy was used to study the site-specific glycosylation. No glycosylation was found at Asn264, whilst high mannose glycans were only detected at Asn275, tri-antennary glycans were exclusively observed at Asn99 and Asn252, and non-fucosylated complex glycans were detected at Asn99. The results showed similar glycosylation profiles between the two IgE samples. These observations, together with previous knowledge of IgE glycosylation, imply that IgE glycosylation is similarly regulated among healthy control, allergy and PGM3 related hyper IgE syndrome

    High throughput method for analysis of repeat number for 28 phase variable loci of C. jejuni strain NCTC11168

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    Mutations in simple sequence repeat tracts are a major mechanism of phase variation in several bacterial species including Campylobacter jejuni. Changes in repeat number of tracts located within the reading frame can produce a high frequency of reversible switches in gene expression between ON and OFF states. The genome of C. jejuni strain NCTC11168 contains 29 loci with polyG/polyC tracts of seven or more repeats. This protocol outlines a method for rapidly determining ON/OFF states of these 28 phase-variable loci in a large number of individual colonies. The method combines a series of multiplex PCR assays with a GeneScan assay and automated extraction of tract length, repeat number and expression state. This high throughput, multiplex assay has utility for detecting shifts in phase variation states within and between populations over time and for exploring the effects of phase variation on adaptation to differing selective pressures. An important output of this assay is combinatorial expression states that cannot be determined by other methods. This method can be adapted to analysis of phase variation in other C. jejuni strains and in a diverse range of bacterial species

    Targeted glycoproteomic identification of cancer cell glycosylation

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    GalMBP is a fragment of serum mannose-binding protein that has been modified to create a probe for galactose-containing ligands. Glycan array screening demonstrated that the carbohydrate-recognition domain of GalMBP selectively binds common groups of tumor-associated glycans, including Lewis-type structures and T antigen, suggesting that engineered glycan-binding proteins such as GalMBP represent novel tools for the characterization of glycoproteins bearing tumor-associated glycans. Blotting of cell extracts and membranes from MCF7 breast cancer cells with radiolabeled GalMBP was used to demonstrate that it binds to a selected set of high molecular weight glycoproteins that could be purified from MCF7 cells on an affinity column constructed with GalMBP. Proteomic and glycomic analysis of these glycoproteins by mass spectrometry showed that they are forms of CD98hc that bear glycans displaying heavily fucosylated termini, including Lewisx and Lewisy structures. The pool of ligands was found to include the target ligands for anti-CD15 antibodies, which are commonly used to detect Lewisx antigen on tumors, and for the endothelial scavenger receptor C-type lectin, which may be involved in tumor metastasis through interactions with this antigen. A survey of additional breast cancer cell lines reveals that there is wide variation in the types of glycosylation that lead to binding of GalMBP. Higher levels of binding are associated either with the presence of outer-arm fucosylated structures carried on a variety of different cell surface glycoproteins or with the presence of high levels of the mucin MUC1 bearing T antigen

    Molecular Characterization of Transcriptional Regulation of rovA by PhoP and RovA in Yersinia pestis

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    BACKGROUND: Yersinia pestis is the causative agent of plague. The two transcriptional regulators, PhoP and RovA, are required for the virulence of Y. pestis through the regulation of various virulence-associated loci. They are the global regulators controlling two distinct large complexes of cellular pathways. METHODOLOGY/PRINCIPAL FINDINGS: Based on the LacZ fusion, primer extension, gel mobility shift, and DNase I footprinting assays, RovA is shown to recognize both of the two promoters of its gene in Y. pestis. The autoregulation of RovA appears to be a conserved mechanism shared by Y. pestis and its closely related progenitor, Y. pseudotuberculosis. In Y. pestis, the PhoP regulator responds to low magnesium signals and then negatively controls only one of the two promoters of rovA through PhoP-promoter DNA association. CONCLUSIONS/SIGNIFICANCE: RovA is a direct transcriptional activator for its own gene in Y. pestis, while PhoP recognizes the promoter region of rovA to repress its transcription. The direct regulatory association between PhoP and RovA bridges the PhoP and RovA regulons in Y. pestis
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