Hausdorff Measures and Functions of Bounded Quadratic Variation

To each function $f$ of bounded quadratic variation ($f\in V_2$) we associate a Hausdorff measure $\mu_f$. We show that the map $f\to\mu_f$ is locally Lipschitz and onto the positive cone of $\mathcal{M}[0,1]$. We use the measures $\{\mu_f:f\in V_2\}$ to determine the structure of the subspaces of $V_2^0$ which either contain $c_0$ or the square stopping time space $S^2$.Comment: 36 pages This is a revised version with few typos and linguistic correction

Polymeric microcapsules with switchable mechanical properties for self-healing concrete: synthesis, characterisation and proof of concept

Microcapsules, with sodium silicate solution as core, were produced using complex coacervation in a double, oil-in-water-in oil, emulsion system. The shell material was a gelatin–acacia gum crosslinked coacervate and the produced microcapsules had diameters ranging from 300 to 700 μm. The shell material designed with switchable mechanical properties. When it is hydrated exhibits soft and ‘rubbery’ behaviour and, when dried, transitions to a stiff and ‘glassy’ material. The microcapsules survived drying and rehydrating cycles and preserved their structural integrity when exposed to highly alkaline solutions that mimic the pH environment of concrete. Microscopy revealed that the shell thickness of the microcapsules varies across their perimeter from 5 to 20 μm. Thermal analysis showed that the produced microcapsules were very stable up to 190 °C. Proof of concept investigation has demonstrated that the microcapsules successfully survive and function when exposed to a cement-based matrix. Observations showed that the microcapsules survive mixing with cement and rupture successfully upon crack formation releasing the encapsulated sodium silicate solution.Financial support from the Engineering and Physical Sciences Research Council (EPSRC—United Kingdom) for this study (Project Ref. EP/K026631/1—‘Materials for Life’) is gratefully acknowledged

Transnational Solidarity, Migration, and the Refugee Crisis: (In)Formal Organising and Political Environments in Greece, Germany, and Denmark

Over the last decade, the unprecedented influx of refugees and migrants into the European Union has posed a significant challenge to Europe, with solidarity being contested at two fronts: first, the question of solidarity with refugees in terms of meeting adequate measures of protection and satisfying their elementary needs; and second, the question of solidarity within the European Union in terms of sharing the costs and burden of hosting these refugees among the member states. One driving factor of these contestations is that the solidarity challenge in facing the ‘refugee crisis’ is taken up differently in transit countries in the South of Europe and destination countries in the North. Wishing to shed light on how national contexts impact transnational solidarity organising, we draw on a fresh set of cross-national evidence from a random sample of 277 transnational solidarity organisations (TSOs) in Greece, Germany, and Denmark. The aim is to illustrate the effects of political opportunities and threats during the 2007–2016 crises period on migration-related solidarity activities organised by TSOs. We will do so through tri-national comparisons tracing the patterns in which migration-related TSOs appear through time. The data used is produced in the context of the TRANSSOL project by a new methodological approach (action organisation analysis) based on hubs-retrieved organisational websites and their subsequent content analysis

Special issue on satellite communication systems and networking

[No abstract available

Engaging farmers on climate risk through targeted integration of bio-economic modelling and seasonal climate forecasts

Seasonal climate forecasts (SCFs) can be used to identify appropriate risk management strategies and to reduce the sensitivity of rural industries and communities to climate risk. However, these forecasts have low utility among farmers in agricultural decision making, unless translated into a more understood portfolio of farm management options. Towards achieving this translation, we developed a mathematical programming model that integrates seasonal climate forecasts to assess ‘what-if?’ crop choice scenarios for famers. We used the Rayapalli village in southern India as a case study. The model maximises expected profitability at village level subject to available resource constraints. The main outputs of the model are the optimal cropping patterns and corresponding agricultural management decisions such as fertiliser, biocide, labour and machinery use. The model is set up to run in two steps. In the first step the initial climate forecast is used to calculate the optimal farm plan and corresponding agricultural management decisions at a village scale. The second step uses a ‘revised forecast’ that is given six weeks later during the growing season. In scenarios where the forecast provides no clear expectation for a dry or wet season the model utilises the total agricultural land available. A significant area is allocated to redgram (pigeon pea) and the rest to maize and paddy rice. In a forecast where a dry season is more probable, cotton is the predominant crop selected. In scenarios where a ‘normal’ season is expected, the model chooses predominantly cotton and maize in addition to paddy rice and redgram. As part of the stakeholder engagement process, we operated the model in an iterative way with participating farmers. For ‘deficient’ rainfall season, farmers were in agreement with the model choice of leaving a large portion of the agriculture land as fallow with only 40 ha (total area 136 ha) of cotton and subsistence paddy rice area. While the model crop choice was redgram in ‘above normal and wet seasons, only a few farmers in the village favoured redgram mainly because of high labour requirements, and the farmers perceptions about risks related to pests and diseases. This highlighted the discrepancy between the optimal cropping pattern, calculated with the model and the farmer's actual decisions which provided useful insights into factors affecting farmer decision making that are not always captured by models. We found that planning for a ‘normal’ season alone is likely to result in losses and opportunity costs and an adaptive climate risk management approach is prudent. In an interactive feedback workshop, majority of participating farmers agreed that their knowledge on the utility and challenges of SCF have highly improved through the participation in this research and most agreed that exposure to the model improved their understanding of the role of SCF in crop choice decisions and that the modelling tool was useful to discuss climate risk in agriculture

Large Scale Application of Self-Healing Concrete: Design, Construction, and Testing

Materials for Life (M4L) was a 3 year, EPSRC funded, research project carried out by the Universities of Cardiff, Bath and Cambridge to investigate the development of self-healing cementitious construction materials. This paper describes the UK's first site trial of self-healing concrete, which was the culmination of that project. The trial comprised the in-situ construction of five concrete panels using a range of self-healing technologies within the site compound of the A465 Heads of the Valleys Highway upgrading project. Four self-healing techniques were used both individually and in combination with one another. They were: (i) the use of microcapsules developed by the University of Cambridge, in collaboration with industry, containing mineral healing agents, (ii) bacterial healing using the expertise developed at Bath University, (iii) the use of a shape memory polymer (SMP) based system for crack closure and (iv) the delivery of a mineral healing agent through a vascular flow network. Both of the latter, (iii) and (iv), were the product of research undertaken at Cardiff University. This paper describes the design, construction, testing, and monitoring of these trial panels and presents the primary findings of the exercise. The challenges that had to be overcome to incorporate these self-healing techniques into full-scale structures on a live construction site are highlighted, the impact of the different techniques on the behavior of the panels when subject to loading is presented and the ability of the techniques used to heal the cracks that were generated is discussed.The work reported in this paper was carried out as part of the EPSRC funded project Materials for Life (M4L), reference EP/K026631/1 and supported with PhD studentship funding from Costain Group PLC

The influence of the Evros River on the recent sedimentation of the inner shelf of the NE Aegean Sea

Abstract The transboundary Evros River discharges into the Alexandroupolis Gulf, located in the inner shelf of the northeastern Aegean Sea, where it has formed an extended delta. Grain-size and mineralogical analyses of five sediment cores, collected in the subaqueous delta, provide the following information about recent sedimentation processes in the northeastern part of the Aegean shelf: (a) river mouth deposits, consisting of coarse-grained sediments, are mainly deposited in front of the active mouth, whilst some sandy material is expected to be transported alongshore by nearshore currents; (b) delta front deposits are characterised by fine-grained sediments that include evidence of human activities which have taken place, in a more intense way, since the 1950s; and (c) prodelta deposits are represented by almost uniform riverine mud that cover the pre-existed relict sands of the shelf, indicating also the limit (some 15 km to the SW) of the influence of riverine sedimentation on the seabed of the inner shelf of the Alexandroupolis Gulf

Elastic Stable Intramedullary Nailing (ESIN), Orthoss® and Gravitational Platelet Separation - System (GPS®): An effective method of treatment for pathologic fractures of bone cysts in children

<p>Abstract</p> <p>Background</p> <p>The different treatment strategies for bone cysts in children are often associated with persistence and high recurrence rates of the lesions. The safety and clinical outcomes of a combined mechanical and biological treatment with elastic intramedullary nailing, artificial bone substitute and autologous platelet rich plasma are evaluated.</p> <p>Methods</p> <p>From 02/07 to 01/09 we offered all children with bone cysts the treatment combination of elastic intramedullary nailing (ESIN), artificial bone substitute (Orthoss^®) and autologous platelet rich plasma, concentrated by the Gravitational Platelet Separation (GPS^®) - System. All patients were reviewed radiologically for one year following the removal of the intramedullary nailing, which was possible because of cyst obliteration.</p> <p>Results</p> <p>A cohort of 12 children (4 girls, 8 boys) was recruited. The mean patient age was 11.4 years (range 7-15 years). The bone defects (ten humeral, two femoral) included eight juvenile and four aneurysmal bone cysts. Five patients suffered from persistent cysts following earlier unsuccessful treatment of humeral bone cyst after pathologic fracture; the other seven presented with acute pathologic fractures. No peri- or postoperative complications occurred. The radiographic findings showed a total resolution of the cysts in ten cases (Capanna Grade 1); in two cases a small residual cyst remained (Capanna Grade 2). The intramedullary nails were removed six to twelve months (mean 7.7) after the operation; in one case, a fourteen year old boy (Capanna Grade 2), required a further application of GPS^®and Orthoss^®to reach a total resolution of the cyst. At follow-up (20-41 months, mean 31.8 months) all patients showed very good functional results and had returned to sporting activity. No refracture occurred, no further procedure was necessary.</p> <p>Conclusions</p> <p>The combination of elastic intramedullary nailing, artificial bone substitute and autologous platelet rich plasma (GPS^®) enhances the treatment of bone cysts in children, with no resulting complications.</p