3,347 research outputs found

    Getting more than a fair share: nutrition of worker larvae related to social parasitism in the Cape honey bee Apis mellifera capensis

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    Besides activation of ovaries and thelytokous reproduction of Cape workers, larval nutrition is an important aspect in parasitism of the African honey bee. When reared by workers of other subspecies, Cape larvae receive more food which is slightly more royal jelly-like. This results in worker-queen intermediates, with reduced pollen combs, enlarged spermathecae and higher numbers of ovarioles. The intermediates weigh more and develop faster than normal workers. The appearance of worker-queen intermediates probably affects parasitism of the African honey bee colonies by Cape workers. Different levels of larval nutrition resulting in less distinct caste differentiation may be important for the reproductive success of Cape workers in their own colonies. Similar processes, albeit less pronounced, may occur in colonies of other subspecies

    Beyond you and I: role play and reflection-in-action in communication training

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    This article will explore the development of communication training within nurse training. Beginning by outlining current thinking around this practice, it then discusses Schön’s notion of reflective practice and its frequently cited relevance to nursing before pointing out some of its limitations. In particular, it looks at the limitations of the individual being able to critically reflect on their self within a broader social context. Drawing on the theories of Habermas and Bourdieu, it suggests that encouraging a greater awareness of one’s own social context, and hence of one’s own subject position, would develop a deeper awareness of other potential perspectives and a better ability to listen to patients. Finally, it argues for the use of role play in assisting nurses to gain such awareness, particularly in difficult clinical situations such as end-of-life care

    The commercial crisis of 1847

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    This study attempts to provide a descriptive and analytical account of the origins of the British Commercial Crisis of 1847. The approach adopted is as follows: An introductory chapter outlines the main questions to be studied and provides a brief narrative account of the development of the crisis. Subsequent chapters examine the develop­ment of the crisis through individual sectors of the economy and by way of certain key economic variables. Chapters II to VI concentrate on aspects of the railway investment boom, aggregate income and consumption, and the experience of four major industries - house-building, coal-mining, and iron and cotton goods manufacture. Chapter VII looks at money and banking aspects of the crisis and deals especially with the role of the Bank of England. It also considers other parts of the banking system as well as some aspects of railway investment not discussed in earlier chapters. Questions of trade and the balance of payments are examined in Chapter VIII. The chapter also considers the immediate causes of failure among mercantile houses during the crisis of 1847. The final chapter summarizes the principal conclusions contained in the preceding chapters

    Engineering Dehydrated Amino Acid Residues in the Antimicrobial Peptide Nisin

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    The small antimicrobial peptide nisin, produced by Lactococcus lactis, contains the uncommon amino acid residues dehydroalanine and dehydrobutyrine and five thio ether bridges. Since these structures are posttranslationally formed from Ser, Thr, and Cys residues, it is feasible to study their role in nisin function and biosynthesis by protein engineering. Here we report the development of an expression system for mutated nisin Z (nisZ) genes, using nisin A producing L. lactis as a host. Replacement by site-directed mutagenesis of the Ser-5 codon in nisZ by a Thr codon, led to a mutant with a dehydrobutyrine instead of a dehydroalanine residue at position 5, as shown by NMR. Its antimicrobial activity was 2-10-fold lower relative to wild-type nisin Z, depending on the indicator strain used. In another mutagenesis study a double mutation was introduced in the nisZ gene by replacing the codons for Met-17 and Gly-18 by codons for Gln and Thr, respectively, as in the third lanthionine ring of the related antimicrobial peptide subtilin from Bacillus subtilis. This resulted in the simultaneous production of two mutant species, one containing a Thr residue and the other containing a dehydrobutyrine residue at position 18, both having different bacteriocidal properties.

    Promise and pitfalls in the application of big data to occupational and environmental health

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    EditorialIs “big data” merely a catchphrase, or does the approach hold real promise in informing occupational and environmental health? Can challenges related to messy and unrepresentative data and spurious findings be overcome

    Design and Fabrication of Cell-laden Gelatin Methacrylated Hydrogel Scaffold for Improving Biotransportation

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    One of the main goals of Tissue Engineering (TE), which has been developed rapidly over the recent years, is to re-create organs or tissues in vitro or in vivo with mimicked the anatomy and functions of body systems. Nowadays, replacing damaged tissues or organs has been a main focus in this field for addressing a significant shortage of donor tissues. Vascularisation plays a crucial role in supplying cells and tissue with essential oxygen and nutrients and removing waste products from the engineered tissue constructs. Any issue in nutrient perfusion and mass transport could significantly restrict construct development to dimensions smaller than clinically useful size, thus limiting the ability for in vivo integration. The main objectives of this study are to develop a novel framework for computational design using topology optimisation and microfabrication of 3D scaffolds using gelatin-based hydrogels (GelMa), allowing artificial vascularisation in vitro for testing if the framework is valid through the investigation into cellular viability inside the construct. In this thesis, computational models were first generated to simulate oxygen transport through solving the diffusion equation. The diffusion models are then used to optimise scaffold topology. By means of microfabrication technologies, hydrogel-based constructs were fabricated to prototype the sophisticated scaffolds. Cellular viability study was also performed to validate computational simulations and design. The results showed a higher cellular survival rate in optimally patterned constructs than the control. In summary, the work presented here is not only technically simple and cost-effective, but also establishes an effective approach to the design and fabrication of a vascularised biodegradable and scaffold-free constructs. The proposed methodology will be of considerable implication for engineering bulk tissue constructs which require sufficient ongoing vascularization in the future

    Results of cross-faculty 'capstone' assessments involving nursing and performing arts students

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    This article describes how ‘capstone’ assessments were created to provide two different student groups, nursing and performing arts students, with a lived experience of learning together about their own fields of practice. Capstone assessments combine ‘live’ human simulation with self‑reflection and peer review. A capstone assessment is the integration of a body of relatively fragmented knowledge and learning to form a unified whole and can be used as a transitional assessment and a bridging experience to connect knowledge between modules or courses. The capstone assessments involved two faculties and four modules, three nursing and one performing arts. Case studies were designed to represent real-life situations that students were likely to encounter during their careers, either playing a patient as an actor or performing a caring role as a nurse. Assessments for the capstone simulation were formative, and involved the students engaging in self-reflection and peer review. Videos were available to enhance the self-reflection and peer-review process. Evaluation was undertaken through verbal feedback during debrief, written feedback, video footage and nursing student and acting student peer review. The experience of capstone assessments for two diverse student groups provided valuable learning from their own and from a different group outside their subject area
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