328 research outputs found

    Exploring leadership in early childhood practice: summary of original research

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    This is a summary of the research undertaken for this project. The results of our research project are presented within the book ‘Leading in Early Childhood’, published by Sage, 2016, and are being prepared for presentation in early childhood journal articles and at academic and practitioner conferences

    Anti-mycobacterial assessment and characterization of 5-O-caffeoylquinic acid methyl ester and rutin from Pavetta crassipes

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    Pavetta crassipes leaf (Fam. Rubiaceae) is used as part of a combination herbal remedy for the treatment of tuberculosis (TB) and other respiratory infections in Nigerian ethno medicine. However, little scientific data is available to support the use in ethnomedical therapy so the objective of the study was to assess the antitubercular property and to identify the bioactive components. The dried powdered leaf was sequentially extracted with solvents to obtain hexane, dichloromethane, methanol and water extracts. Following which, the extracts were then screened against Mycobacterium aurum, a rapidly growing saprophytic mycobacterium species for activity. The methanol extract exhibited inhibitory activity at an MIC value of 250 ”g/mL against M. aurum and two known polyphenolic compounds were isolated as 5-O-caffeoylquinic acid methyl ester and quercetin-3-rutinoside (rutin). Reversed phase semi-preparative HPLC, mass spectrometry and 1H and 13C NMR techniques were utilized in isolating and characterizing the two components. The assignments of the structures were consistent with data from the literature. The study has shown that the methanol extract has some activity and hyphenation of LC-MS can be used for the isolation of polyphenols from the methanol fraction without a rigorous purification process

    Thermo-Mechanical Fatigue Crack Growth of RR1000

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    Non-isothermal conditions during flight cycles have long led to the requirement for thermo-mechanical fatigue (TMF) evaluation of aerospace materials. However, the increased temperatures within the gas turbine engine have meant that the requirements for TMF testing now extend to disc alloys along with blade materials. As such, fatigue crack growth rates are required to be evaluated under non-isothermal conditions along with the development of a detailed understanding of related failure mechanisms. In the current work, a TMF crack growth testing method has been developed utilising induction heating and direct current potential drop techniques for polycrystalline nickel-based superalloys, such as RR1000. Results have shown that in-phase (IP) testing produces accelerated crack growth rates compared with out-of-phase (OOP) due to increased temperature at peak stress and therefore increased time dependent crack growth. The ordering of the crack growth rates is supported by detailed fractographic analysis which shows intergranular crack growth in IP test specimens, and transgranular crack growth in 90° OOP and 180° OOP tests. Isothermal tests have also been carried out for comparison of crack growth rates at the point of peak stress in the TMF cycles

    Effect of moisture on the reactivity of alpha-tricalcium phosphate

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    The ability of the high-temperature polymorph of tricalcium phosphate, a-TCP, to hydrolyse to calcium-deficient hydroxyapatite underlies many developments in the field of synthetic bone grafts, including calcium phosphate cements, foams, and self-setting inks. The objective of the present work was to investigate the effect of humidity on a-TCP powder reactivity. The results showed that a 3-week incubation at high relative humidity (80%) had no impact on reactivity, but, as the incubation was prolonged, the powder started to hydrolyse. This reactivity was associated to the presence of defects and to an amorphous phase induced during powder milling. Moisture studies performed under static/dynamic conditions gave comparable water adsorption percentages. The dynamic studies further proved irreversible water sorption, indicating that some water molecules reacted with the powder after short incubation times. Taken together, these results demonstrate that, although a-TCP powder adsorbs water from moisture immediately, the impact on reactivity appears only after several weeks of storage.Peer ReviewedPostprint (published version

    Analysis of the impact of Colony Stimulating Factor (CSF)-1 administration in adult rats using a novel Csf1r-mApple reporter gene

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    Macrophages are present in large numbers in every tissue in the body where they play critical roles in development and homeostasis. They exhibit remarkable phenotypic and functional diversity, underpinning their adaptation to specialized roles in each tissue niche. CSF1, signaling through the CSF1 receptor, which is restricted to monocyte-macrophage lineage cells in adults, is a critical growth factor controlling macrophage proliferation, differentiation, and many aspects of mature macrophage function. We have generated a macrophage reporter rat, utilizing a construct containing elements of the mouse Csf1r promoter and the highly conserved Fms intronic regulatory element to drive mApple fluorescent protein expression. Csf1r-mApple was robustly expressed in monocyte-macrophage lineage cells in rat bone marrow (BM), peripheral blood, and tissues, with detectable expression in granulocytes and B cells and no evidence of expression in hematopoietic precursors or non-hematopoietic cells. Here, we use the Csf1r-mApple transgene to highlight and dissect the abundance and heterogeneity of rat tissue macrophage populations, and to demonstrate parallel increases in blood monocytes and multiple tissue macrophage populations, including BM, liver, spleen, and lung, in response to CSF1 treatment in vivo. The Csf1r-mApple rat is a novel tool enabling analysis of rat macrophages in situ by direct imaging and providing an additional phenotypic marker to facilitate exploration of rat tissue macrophage phenotypic and functional heterogeneity

    Clinical findings in two cases of atypical scrapie in sheep: a case report

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    BACKGROUND: Atypical scrapie is a recently recognised form of transmissible spongiform encephalopathy of sheep that differs from classical scrapie in its neuropathological and biochemical features. Most cases are detected in apparently healthy sheep and information on the clinical presentation is limited. CASE PRESENTATION: This report describes the clinical findings in two sheep notified as scrapie suspects and confirmed as atypical scrapie cases by immunohistochemistry and Western immunoblotting. Although both sheep displayed signs suggestive of a cerebellar dysfunction there was considerable variation in the individual clinical signs, which were similar to classical scrapie. CONCLUSION: Any sheep presenting with neurological gait deficits should be assessed more closely for other behavioural, neurological and physical signs associated with scrapie and their presence should lead to the suspicion of scrapie

    Comprehensive transcriptional profiling of the gastrointestinal tract of ruminants from birth to adulthood reveals strong developmental stage specific gene expression

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    One of the most significant physiological challenges to neonatal and juvenile ruminants is the development and establishment of the rumen. Using a subset of RNA-Seq data from our high-resolution atlas of gene expression in sheep (Ovis aries) we have provided the first comprehensive characterization of transcription of the entire gastrointestinal (GI) tract during the transition from pre-ruminant to ruminant. The dataset comprises 164 tissue samples from sheep at four different time points (birth, one week, 8 weeks and adult). Using network cluster analysis we illustrate how the complexity of the GI tract is reflected in tissueand developmental stage-specific differences in gene expression. The most significant transcriptional differences between neonatal and adult sheep were observed in the rumen complex. Comparative analysis of gene expression in three GI tract tissues from age-matched sheep and goats revealed species-specific differences in genes involved in immunity and metabolism. This study improves our understanding of the transcriptomic mechanisms involved in the transition from pre-ruminant to ruminant by identifying key genes involved in immunity, microbe recognition and metabolism. The results form a basis for future studies linking gene expression with microbial colonization of the developing GI tract and provide a foundation to improve ruminant efficiency and productivity through identifying potential targets for novel therapeutics and gene editing
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