Establishing Industrial Advisory Boards using a practice transfer model

The Faculty of Mathematics and Physical Sciences at the University of Leeds established discipline-based Industrial Advisory Boards (IABs) with the support of the National HE STEM Programme. The Faculty was advised by the University of Sheffield, which had also recently established an IAB under the National HE STEM Programme. Using a Practice Transfer Adoption Scheme (PTAS), the University of Sheffield was able to share its experience and facilitate the process at the University of Leeds and at a number of other institutions nationally. Separate advisory boards were established in the Schools of Chemistry, Mathematics and Physics, although there is some overlap in membership. Each of the IABs considers both teaching and research activities. There is a strong focus on developing a better understanding of skills development within the undergraduate programmes to meet the needs of employers. Industrial projects, case studies and guest lectures have all enhanced the curricula and provided students with some commercial insight. Opportunities for interaction between the board and current students, such as networking events, are being developed and piloted. Practice Transfer Adoption proved to be a very effective and efficient model for initiating and implementing change. Through the sharing of good practice and mentoring, timescales for implementation were significantly shorter than the timescales required to implement new initiatives without a PTA model

Hunter-gatherers adjust mobility to maintain contact under climatic variation

Population density and mobility are fundamental population parameters for hunter-gatherer groups, and their reconstruction for prehistoric populations has long been an aim of archaeological research. This endeavour has become more important than ever in recent years, with the recognition that these parameters play a key role in determining rates of cultural transmission. Potential archaeological proxies for population density and mobility are often hard to interpret, creating a need for more generic, reliable, and easily calculated indicators. Climatic variables provide considerable promise in this area, and the analyses reported here test the efficacy of six climatic variables as potential predictors. Significant predictors are then incorporated in path analyses that assess the causal relationships between climatic variables, population density, and mobility. Results suggest that the previously established strong reciprocal relationship between population density and mobility is not due purely to common determination by climatic variables. Instead, the best supported model is consistent with the hypothesis that hunter-gatherers adjust levels of mobility so as to maintain contact with neighbouring groups at varying population densities. This ensures that opportunities for cultural transmission are maintained at similar levels regardless of climatic variation. The results lead to a number of archaeologically testable predictions concerning the relationships between climatic variables, population density, mobility, and assemblage complexity

Evolving conformity: conditions favouring conformist social learning over random copying

There is a growing interest in the relative benefits to the learner of the different social learning strategies used to transmit information between conspecifics, and in the extent to which they require input from individual learning. To date, theoretical models have tended to examine the success of particular strategies in relation to specific parameters or circumstances. This study employs individual-based simulations to derive the optimal proportion of individual learning that co-exists with random copying and conformist social learning strategies in populations experiencing wide-ranging variation in levels of environmental change, reproductive turnover, learning error, and individual learning costs. Predictions derived from the literature – that optimal levels of individual learning will be higher for both strategies when the rate of environmental change is higher, and when reproductive turnover and individual learning costs are lower, are supported. Contrary to the theoretical prediction, optimal levels of individual learning are sometimes higher under higher levels of learning error, particularly when reproductive rates are low. Results for the two strategies are qualitatively similar, but demonstrate numerous parameter combinations under which random copying is fitter than conformist social learning. Contrary to established expectations, the strategy employing the lesser proportion of individual learning is not always the fittest

Moisture effects on the bending fatigue of laminated composites

This paper investigated the effect of moisture ingress on the bending fatigue of laminated composites. An accelerated testing method was developed to investigate the correlation between composite fatigue and moisture diffusion effects. Unidirectional and cross-ply laminated CFRP composites were manufactured in autoclave, and then submerged in both fresh and seawater for various periods until moisture saturation. Quasi-static and cyclic tests were carried out in both air and wet environment, and the failure mechanisms were investigated using visual and microscopic methods. Additionally, a robust 2D Finite Element model (FEA) was developed to simulate the fatigue crack propagation based on virtual crack closure technique (VCCT), while a 3D FEA model was developed to investigate the edge effect on fatigue crack propagation. The experimental observations gave a good agreement with the FEA models. The study showed that the bending fatigue failure was due to the so-called buckling-driven delamination, and the fatigue life was reduced significantly owing to the combination of edge effect and capillary effect. The fatigue test indicated that the fatigue resistance was degraded one stress level due to the water ingress, e.g. from 80% ultimate flexural strength (UFS) to 65% UFS. Therefore, a 4-step fatigue failure theory was proposed to explain the moisture effects on the crack propagation under bending fatigue

Numerical analysis of the thermomechanical behaviour of an integrally water-heated tool for composite manufacturing

Integrally water-heated tooling is one of the technologies available for ‘out-of-autoclave’ processing of advanced thermoset polymer composites. Temperature variation and temperature cycling, during heating and cooling, affect the properties of tool material and may produce undesirable thermal effects that degrade the tool durability and performance, especially when the tool construction involves various materials. Hence, in the current study, the performance and the thermomechanical behaviour of an integrally water-heated tool have been investigated using finite element analysis method. The intended tool, in the current study, consists different materials of composite and metals and is designed to heat up to 90℃. Linear mechanical properties, coefficient of thermal expansions and transient heating curve of each tool part are determined experimentally and set during the numerical analysis of tool structure to calculate the static thermal load effects of deformation, stress and strain. Comparing the numerical thermal effects with the ultimate stresses and strains of the tool, materials concluded that no failure occurs with regard to static thermal loads. However, the calculated stresses are as much as the lowest magnitude of safety relates to the tool mould part made of Alepoxy. </jats:p

Moisture effects on the bending fatigue of laminated composites

This paper investigated the effect of moisture ingress on the bending fatigue of laminated composites. An accelerated testing method was developed to investigate the correlation between composite fatigue and moisture diffusion effects. Unidirectional and cross-ply laminated CFRP composites were manufactured in autoclave, and then submerged in both fresh and seawater for various periods until moisture saturation. Quasi-static and cyclic tests were carried out in both air and wet environment, and the failure mechanisms were investigated using visual and microscopic methods. Additionally, a robust 2D Finite Element model (FEA) was developed to simulate the fatigue crack propagation based on virtual crack closure technique (VCCT), while a 3D FEA model was developed to investigate the edge effect on fatigue crack propagation. The experimental observations gave a good agreement with the FEA models. The study showed that the bending fatigue failure was due to the so-called buckling-driven delamination, and the fatigue life was reduced significantly owing to the combination of edge effect and capillary effect. The fatigue test indicated that the fatigue resistance was degraded one stress level due to the water ingress, e.g. from 80% ultimate flexural strength (UFS) to 65% UFS. Therefore, a 4-step fatigue failure theory was proposed to explain the moisture effects on the crack propagation under bending fatigue

Habitat structure: a fundamental concept and framework for urban soil ecology

Habitat structure is defined as the composition and arrangement of physical matter at a location. Although habitat structure is the physical template underlying ecological patterns and processes, the concept is relatively unappreciated and underdeveloped in ecology. However, it provides a fundamental concept for urban ecology because human activities in urban ecosystems are often targeted toward management of habitat structure. In addition, the concept emphasizes the fine-scale, on-the-ground perspective needed in the study of urban soil ecology. To illustrate this, urban soil ecology research is summarized from the perspective of habitat structure effects. Among the key conclusions emerging from the literature review are: (1) habitat structure provides a unifying theme for multivariate research about urban soil ecology; (2) heterogeneous urban habitat structures influence soil ecological variables in different ways; (3) more research is needed to understand relationships among sociological variables, habitat structure patterns and urban soil ecology. To stimulate urban soil ecology research, a conceptual framework is presented to show the direct and indirect relationships among habitat structure and ecological variables. Because habitat structure serves as a physical link between sociocultural and ecological systems, it can be used as a focus for interdisciplinary and applied research (e.g., pest management) about the multiple, interactive effects of urbanization on the ecology of soils

A role for the tfs3 ICE-encoded type IV secretion system in pro-inflammatory signalling by the Helicobacter pylori Ser/Thr kinase, CtkA

Two distinct type IV secretion systems (T4SSs) can be identified in certain Helicobacter pylori strains, encoded on mobile genetic elements termed tfs3 and tfs4. Although their function remains unknown, both have been implicated in clinical outcomes of H. pylori infection. Here we provide evidence that the Tfs3 T4SS is required for activity of the pro-inflammatory Ser/Thr kinase protein, CtkA, in a gastric epithelial cell infection model. Previously, purified recombinant CtkA protein has been shown to upregulate NF-kappaB signalling and induce TNF-alpha and IL-8 cytokine secretion from cultured macrophages suggesting that it may potentiate the H. pylori-mediated inflammatory response. In this study, we show that CtkA expressed from its native host, H. pylori has a similar capacity for stimulation of a pro-inflammatory response from gastric epithelial cells. CtkA interaction was found to be dependent upon a complement of tfs3 T4SS genes, but independent of the T4SSs encoded by either tfs4 or the cag pathogenicity island. Moreover, the availability of CtkA for host cell interaction was shown to be conditional upon the carboxyl-terminus of CtkA, encoding a putative conserved secretion signal common to other variably encoded Tfs3 proteins. Collectively, our observations indicate a role for the Tfs3 T4SS in CtkA-mediated pro-inflammatory signalling by H. pylori and identify CtkA as a likely Tfs3 T4SS secretion substrate

Accretion Disks Around Black Holes: Twenty Five Years Later

We study the progress of the theory of accretion disks around black holes in last twenty five years and explain why advective disks are the best bet in explaining varied stationary and non-stationary observations from black hole candidates. We show also that the recently proposed advection dominated flows are incorrect.Comment: 30 Latex pages including figures. Kluwer Style files included. Appearing in `Observational Evidence for Black Holes in the Universe', ed. Sandip K. Chakrabarti, Kluwer Academic Publishers (DORDRECHT: Holland

Nickel and helium evidence for melt above the core–mantle boundary

High ^(3)He/^(4)He ratios in some basalts have generally been interpreted as originating in an incompletely degassed lower-mantle source. This helium source may have been isolated at the core–mantle boundary region since Earth’s accretion. Alternatively, it may have taken part in whole-mantle convection and crust production over the age of the Earth; if so, it is now either a primitive refugium at the core–mantle boundary or is distributed throughout the lower mantle. Here we constrain the problem using lavas from Baffin Island, West Greenland, the Ontong Java Plateau, Isla Gorgona and Fernandina (Galapagos). Olivine phenocryst compositions show that these lavas originated from a peridotite source that was about 20 per cent higher in nickel content than in the modern mid-ocean-ridge basalt source. Where data are available, these lavas also have high ^(3)He/^(4)He. We propose that a less-degassed nickel-rich source formed by core–mantle interaction during the crystallization of a melt-rich layer or basal magma ocean, and that this source continues to be sampled by mantle plumes. The spatial distribution of this source may be constrained by nickel partitioning experiments at the pressures of the core–mantle boundary