‘I can use things, but I can't make anything’: a qualitative exploration of team networks in the development and implementation of a new undergraduate e-compendium

In higher education, undergraduate teaching materials are increasingly becoming available online. There is a need to understand the complex processes that happen during their production and how social networks between different groups impact on their development. This paper draws on qualitative interviews and participant drawings of their social networks to understand the dynamics of creating a new e-compendium for a four-year online undergraduate nursing programme in Norway. Twenty staff interviews were undertaken to explore views of the e-compendium, the development process and the perceived networks that were formed during this course. Interview data were thematically analysed along with networks drawings. The findings showed three main institutional stakeholder groups emerging: the ‘management team’, ‘design team’ and ‘lecturers’. Analysis of social networks revealed variability of relations both within and between groups. The pedagogical designer, who was part of the design team, was central to communicating with and co-ordinating staff at all levels. The least well connected were the lecturers. To them, the e-compendium challenged and even threatened previously well-established notions of pedagogy. Future development of e-compendiums should account for the perceived lack of time and existing workload of lecturers so they may be involved with the development process

The electro-structural behaviour of yarn-like carbon nanotube fibres immersed in organic liquids.

Yarn-like carbon nanotube (CNT) fibres are a hierarchically-structured material with a variety of promising applications such as high performance composites, sensors and actuators, smart textiles, and energy storage and transmission. However, in order to fully realize these possibilities, a more detailed understanding of their interactions with the environment is required. In this work, we describe a simplified representation of the hierarchical structure of the fibres from which several mathematical models are constructed to explain electro-structural interactions of fibres with organic liquids. A balance between the elastic and surface energies of the CNT bundle network in different media allows the determination of the maximum lengths that open junctions can sustain before collapsing to minimize the surface energy. This characteristic length correlates well with the increase of fibre resistance upon immersion in organic liquids. We also study the effect of charge accumulation in open interbundle junctions and derive expressions to describe experimental data on the non-ohmic electrical behaviour of fibres immersed in polar liquids. Our analyses suggest that the non-ohmic behaviour is caused by progressively shorter junctions collapsing as the voltage is increased. Since our models are not based on any property unique to carbon nanotubes, they should also be useful to describe other hierarchical structures

Common Language Infrastructure for Research (CLIR): Editing and Optimizing .NET Assemblies

Programming language researchers, including code optimizers, have few tools available to manipulate .NET assembly files. This thesis presents the Common Language Infrastructure for Research comprised of three components: the Common Language Engineering Library (CLEL), the Common Language Optimizing Framework (CLOT), and a suite of utility applications. CLEL provides the means to read, edit and write .NET assemblies. CLOT, using the CLEL, provides a framework for code optimization including algorithms and data structures for three traditional optimizations. Decreases in program execution time due to application of these optimizations were achieved

Comparison of Effects of p53 Null and Gain-of-Function Mutations on Salivary Tumors in MMTV-Hras Transgenic Mice

p53 is an important tumor suppressor gene which is mutated in ~50% of all human cancers. Some of these mutants appear to have acquired novel functions beyond merely losing wild-type functions. To investigate these gain-of-function effects in vivo, we generated mice of three different genotypes: MMTV-Hras/p53+/+, MMTV-Hras/p53-/-, and MMTV-Hras/p53R172H/R172H. Salivary tumors from these mice were characterized with regard to age of tumor onset, tumor growth rates, cell cycle distribution, apoptotic levels, tumor histopathology, as well as response to doxorubicin treatment. Microarray analysis was also performed to profile gene expression. The MMTV-Hras/p53-/- and MMTV-Hras/p53R172H/R172H mice displayed similar properties with regard to age of tumor onset, tumor growth rates, tumor histopathology, and response to doxorubicin, while both groups were clearly distinct from the MMTV-Hras/p53+/+ mice by these measurements. In addition, the gene expression profiles of the MMTV-Hras/p53-/- and MMTV-Hras/p53R172H/R172H tumors were tightly clustered, and clearly distinct from the profiles of the MMTV-Hras/p53+/+ tumors. Only a small group of genes showing differential expression between the MMTV-Hras/p53-/- and MMTV-Hras/p53R172H/R172H tumors, that did not appear to be regulated by wild-type p53, were identified. Taken together, these results indicate that in this MMTV-Hras-driven salivary tumor model, the major effect of the p53 R172H mutant is due to the loss of wild-type p53 function, with little or no gain-of-function effect on tumorigenesis, which may be explained by the tissue- and tumor type-specific properties of this gain-of-function mutant of p53

Covalent grafting of molecular catalysts on C₄NₓH_{y} as robust, efficient and well-defined photocatalysts for solar fuel synthesis

The covalent attachment of molecules to 2D materials is an emerging area as strong covalent chemistry offers new hybrid properties and greater mechanical stability compared with nanoparticles. A nickel bis-aminothiophenol catalyst was grafted onto a range of 2D carbon nitrides C₄NₓH_{y} to form noble metal-free photocatalysts for H2 production. The hybrids produce H_{2} beyond 8 days with turnover numbers reaching 1360 based on nickel, a more than 3 fold higher durability than reported molecular catalyst-carbon nitride mixtures, and under longer wavelengths (>475 nm). Time-resolved spectroscopy reveals sub-microsecond electron transfer to the grafted catalyst, six orders of magnitude faster compared with similar reports of non-grafted catalysts. The photoelectrons on the catalyst have a ca. 1000 times longer half-time (7 ms) compared with bare carbon nitride (10 μs). The grafting strategy operates across a range of molecular catalyst-carbon nitride combinations, thus paving the way for robust efficient photocatalysts based on low-cost tunable components

Extending enzyme molecular recognition with an expanded amino acid alphabet

Natural enzymes are constructed from the twenty proteogenic amino acids, which may then require post-translational modification or the recruitment of coenzymes or metal ions to achieve catalytic function. Here, we demonstrate that expansion of the alphabet of amino acids can also enable the properties of enzymes to be extended. A chemical mutagenesis strategy allowed a wide range of non-canonical amino acids to be systematically incorporated throughout an active site to alter enzymic substrate specificity. Specifically, 13 different non-canonical side chains were incorporated at 12 different positions within the active site of N-acetylneuraminic acid lyase (NAL), and the resulting chemically-modified enzymes were screened for activity with a range of aldehyde substrates. A modified enzyme containing a 2,3-dihydroxypropyl cysteine at position 190 was identified that had significantly increased activity for the aldol reaction of erythrose with pyruvate compared with the wild-type enzyme. Kinetic investigation of a saturation library of the canonical amino acids at the same position showed that this increased activity was not achievable with any of the 20 proteogenic amino acids. Structural and modelling studies revealed that the unique shape and functionality of the non-canonical side chain enabled the active site to be remodelled to enable more efficient stabilisation of the transition state of the reaction. The ability to exploit an expanded amino acid alphabet can thus heighten the ambitions of protein engineers wishing to develop enzymes with new catalytic properties

Erratum to: Surface layer proteins from virulent Clostridium difficile ribotypes exhibit signatures of positive selection with consequences for innate immune response

“Upon publication of the original article [1], it was noticed that there was an error in the author name. The author’s name should be "Micheál Mac Aogáin" instead of Micheál MacAogain.

Iron status and Helicobacter pylori infection in symptomatic children: an international multi-centered study.

Abstract Objective: Iron deficiency (ID) and iron deficiency anaemia (IDA) are global major public health problems, particularly in developing countries. Whilst an association between H. pylori infection and ID/IDA has been proposed in the literature, currently there is no consensus. We studied the effects of H. pylori infection on ID/IDA in a cohort of children undergoing upper gastrointestinal endoscopy for upper abdominal pain in two developing and one developed country. Methods: In total 311 children (mean age 10.763.2 years) from Latin America -Belo Horizonte/Brazil (n = 125), Santiago/ Chile (n = 105) -and London/UK (n = 81), were studied. Gastric and duodenal biopsies were obtained for evaluation of histology and H. pylori status and blood samples for parameters of ID/IDA. Results: The prevalence of H. pylori infection was 27.7% being significantly higher (p,0.001) in Latin America (35%) than in UK (7%). Multiple linear regression models revealed H. pylori infection as a significant predictor of low ferritin and haemoglobin concentrations in children from Latin-America. A negative correlation was observed between MCV (r = 20.26; p = 0.01) and MCH (r = 20.27; p = 0.01) values and the degree of antral chronic inflammation, and between MCH and the degree of corpus chronic (r = 20.29, p = 0.008) and active (r = 20.27, p = 0.002) inflammation. Conclusions: This study demonstrates that H. pylori infection in children influences the serum ferritin and haemoglobin concentrations, markers of early depletion of iron stores and anaemia respectively