306 research outputs found

    The identification of archaeological eggshell using peptide markers

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    Avian eggshell survives well in alkaline and neutral soils, but its potential as an archaeological resource remains largely unexplored, mainly due to difficulties in its identification. Here we exploit the release of novel bird genomes and, for the first time on eggshell, use MALDI-ToF (matrix-assisted laser desorption ionisation-time of flight) mass spectrometry in combination with peptide sequencing by LC-MS/MS. The eggshell proteome is revealed as unexpectedly complex, with 5755 proteins identified for a reference collection comprising 23 bird species. We determined 782 m/z markers useful for eggshell identification, 583 of which could be assigned to known eggshell peptide sequences. These were used to identify eggshell fragments recovered from a medieval site at Freeschool Lane, Leicester. We discuss the specificity of the peptide markers and highlight the importance of assessing the level of taxonomic identification achievable for archaeological interpretation

    The effective thermal conductivity of open cell replicated aluminium metal sponges

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    The effective thermal conductivity of aluminium open cell porous materials has been tested using the steady state method. The materials were manufactured using the replication technique producing samples of porosity ranging from 0.57 to 0.77 and pore sizes between 0.7 and 2.4 mm. The effective thermal conductivity was found to decrease with increasing porosity, but there was no notice influence of pore size. The results were found to be in general agreement with similar measurements found in the literature. The differences observed were attributed to the thickness and structure of the material in the matrix. Overall there was better agreement between the experiments than for the correlations and analytical expressions presented in the literature. An empirically derived correlation was obtained for sintered porous materials with porosities ranging from 0.5 to 1.0

    Receptor Activity-modifying Protein-directed G Protein Signaling Specificity for the Calcitonin Gene-related Peptide Family of Receptors.

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    The calcitonin gene-related peptide (CGRP) family of G protein-coupled receptors (GPCRs) is formed through the association of the calcitonin receptor-like receptor (CLR) and one of three receptor activity-modifying proteins (RAMPs). Binding of one of the three peptide ligands, CGRP, adrenomedullin (AM), and intermedin/adrenomedullin 2 (AM2), is well known to result in a Gαs-mediated increase in cAMP. Here we used modified yeast strains that couple receptor activation to cell growth, via chimeric yeast/Gα subunits, and HEK-293 cells to characterize the effect of different RAMP and ligand combinations on this pathway. We not only demonstrate functional couplings to both Gαs and Gαq but also identify a Gαi component to CLR signaling in both yeast and HEK-293 cells, which is absent in HEK-293S cells. We show that the CGRP family of receptors displays both ligand- and RAMP-dependent signaling bias among the Gαs, Gαi, and Gαq/11 pathways. The results are discussed in the context of RAMP interactions probed through molecular modeling and molecular dynamics simulations of the RAMP-GPCR-G protein complexes. This study further highlights the importance of RAMPs to CLR pharmacology and to bias in general, as well as identifying the importance of choosing an appropriate model system for the study of GPCR pharmacology.This work was supported by the National Heart Foundation of New Zealand (H.W.), the School of Biological Sciences, University of Auckland seed fund (H.W.), the BBSRC (G.L. - BB/M00015X/1), (D.P. - BB/M000176/1), (C.A.R. - BB/M006883/1), a BBSRC Doctoral Training Partnership (M.H. – BB/JO14540/1), an MRC Doctoral Training Partnership (I.W. - MR/J003964/1), a Warwick Impact Fund (C.W., G.L.), a Warwick Research Development Fund (C.W., G.L.) grant number (RD13301) and the Warwick Undergraduate Research Scholarship Scheme (A.S and R.H).This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by the American Society for Biochemistry and Molecular Biology

    Children's active play: self-reported motivators, barriers and facilitators

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    Physical activity has important benefits for children's physical health and mental wellbeing, but many children do not meet recommended levels. Research suggests that active play has the potential to make a valuable contribution to children's overall physical activity, whilst providing additional cognitive, social and emotional benefits. However, relatively little is known about the determinants of UK children's active play. Understanding these factors provides the critical first step in developing interventions to increase children's active play, and therefore overall physical activity. Eleven focus groups were conducted with 77, 10-11 year old children from four primary schools in Bristol, UK. Focus groups examined: (i) factors which motivate children to take part in active play; (ii) factors which limit children's active play and (iii) factors which facilitate children's active play. All focus groups were audio-taped and transcribed verbatim. Data were analysed using a thematic approach. Children were motivated to engage in active play because they perceived it to be enjoyable, to prevent boredom, to have physical and mental health benefits and to provide freedom from adult control, rules and structure. However, children's active play was constrained by a number of factors, including rainy weather and fear of groups of teenagers in their play spaces. Some features of the physical environment facilitated children's active play, including the presence of green spaces and cul-de-sacs in the neighbourhood. Additionally, children's use of mobile phones when playing away from home was reported to help to alleviate parents' safety fears, and therefore assist children's active play. Children express a range of motivational and environmental factors that constrain and facilitate their active play. Consideration of these factors should improve effectiveness of interventions designed to increase active play

    The Use of Nanoscale Visible Light-Responsive Photocatalyst TiO2-Pt for the Elimination of Soil-Borne Pathogens

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    Exposure to the soil-borne pathogens Burkholderia pseudomallei and Burkholderia cenocepacia can lead to severe infections and even mortality. These pathogens exhibit a high resistance to antibiotic treatments. In addition, no licensed vaccine is currently available. A nanoscale platinum-containing titania photocatalyst (TiO2-Pt) has been shown to have a superior visible light-responsive photocatalytic ability to degrade chemical contaminants like nitrogen oxides. The antibacterial activity of the catalyst and its potential use in soil pathogen control were evaluated. Using the plating method, we found that TiO2-Pt exerts superior antibacterial performance against Escherichia coli compared to other commercially available and laboratory prepared ultraviolet/visible light-responsive titania photocatalysts. TiO2-Pt-mediated photocatalysis also affectively eliminates the soil-borne bacteria B. pseudomallei and B. cenocepacia. An air pouch infection mouse model further revealed that TiO2-Pt-mediated photocatalysis could reduce the pathogenicity of both strains of bacteria. Unexpectedly, water containing up to 10% w/v dissolved soil particles did not reduce the antibacterial potency of TiO2-Pt, suggesting that the TiO2-Pt photocatalyst is suitable for use in soil-contaminated environments. The TiO2-Pt photocatalyst exerted superior antibacterial activity against a broad spectrum of human pathogens, including B. pseudomallei and B. cenocepacia. Soil particles (<10% w/v) did not significantly reduce the antibacterial activity of TiO2-Pt in water. These findings suggest that the TiO2-Pt photocatalyst may have potential applications in the development of bactericides for soil-borne pathogens
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