On leaders’ presence:interactions and influences within online communities

By conceptualising presence as a behavioural construct, this study explores how online leaders’ presence exerts an influence on online communities and their members. Drawing on qualitative research where five online communities were examined, the findings show that online leaders’ presence is identified in different forms which ultimately may have different impacts on the community and its members. Articulations of leaders’ presence online included interactive, instructive, stimulating and silent and for each the leader was found to exert a different influence on online community members. The theoretical and practical implications of the study are discussed and areas for further research are identified

Graphene inspired sensing devices

Graphene’s exciting characteristics such as high mechanical strength, tuneable electrical prop- erties, high thermal conductivity, elasticity, large surface-to-volume ratio, make it unique and attractive for a plethora of applications including gas and liquid sensing. Adsorption, the phys- ical bonding of molecules on solid surfaces, has huge impact on the electronic properties of graphene. We use this to develop gas sensing devices with faster response time by suspending graphene over large area (cm^2) on silicon nanowire arrays (SiNWAs). These are fabricated by two-step metal-assisted chemical etching (MACE) and using a home-developed polymer-assisted graphene transfer (PAGT) process. The advantage of suspending graphene is the removal of diffusion-limited access to the adsorption sites at the interface between graphene and its support. By modifying the Langmuir adsorption model and fitting the experimental response curves, we find faster response times for both ammonia and acetone vapours. The use of suspended graphene improved the overall response, based on speed and amplitude of response, by up to 750% on average. This device could find applications in biomedical breath analysis for diseases such lung cancer, asthma, kidney failure and more. Taking advantage of the mechanical strength of graphene and using the developed PAGT process, we transfer it on commercial (CMOS) Ion-Sensitive Field-Effect Transistor (ISFET) arrays. The deposition of graphene on the top sensing layer reduces drift that results from the surface modification during exposure to electrolyte while improving the overall performance by up to about 10^13 % and indicates that the ISFET can operate with metallic sensing membrane and not only with insulating materials as confirmed by depositing Au on the gate surface. Post- processing of the ISFET top surface by reactive ion plasma etching, proved that the physical location of trapped charge lies within the device structure. The process improved its overall performance by about 105 %. The post-processing of the ISFET could be applied for sensor performance in any of its applications including pH sensing for DNA sequencing and glucose monitoring.Open Acces

Biorenewable value chain optimisation with multi-layered value chains and advanced analytics

A crucial element of the quest of curbing carbon dioxide emissions is deemed to rely on a biobased economy, which will rely on the development of economically and environmentally sustainable biorefining systems enabling a full exploitation of lignocellulosic biomass (and its macrocomponents such as cellulose, hemicellulose, and lignin) for the co-production of biofuels and bioderived platform chemicals. The thesis aims to develop comprehensive modelling frameworks to provide, through optimisation techniques, holistic decision-making regarding the strategic design and systematic planning of advanced biorefining supply chain networks. Therefore, the modelling of the entire value chain behaviour, involving both upstream and downstream aspects within a temporal and geographical context, is of great importance in this study. A deterministic, spatially explicit, multi-echelon and multi-period Mixed Integer Linear Programming prototype modelling framework is developed for the identification of profitably optimal strategic and operating decisions regarding a full supply chain system, integrated with a technology superstructure of multiple biomass feedstocks, bioproducts and processing portfolios. The potential dimensionality reduction of the resulting large-scale optimisation problem is explored by utilising a bilevel decomposition algorithm. The financial sustainability of such biobased supply chains is further analysed through two-stage stochastic optimisation and risk management models, incorporating biomass cultivation yield uncertainties and expected downside risk, respectively. Finally, greenhouse gas emission factors are added to the prototype modelling approach through a multi-objective optimisation scheme to steer decision-making on biorefining supply chain systems under both economic and environmental criteria, comparing two different solution procedures. The developed models are applied to a Hungarian case study of lignocellulosic biorefining production systems. An additional case study in a Southeastern Romanian region and Marseille, regarding a first-generation biorefining supply chain for the production of castor oil, is undertaken to further examine the compatibility and efficiency of the generic deterministic model.Open Acces

Engineering Novel Detection and Treatment Strategies for Bacterial Therapy of Cancer

Finding and treating cancer is difficult due to limited sensitivity and specificity of current detection and treatment strategies. Many chemotherapeutic drugs are small molecules that are limited by diffusion, making it difficult to reach cancer sites requiring high doses that lead to systemic toxicity and off-target effects. Tomographic detection techniques, like PET, MRI and CT, are good at identifying macroscopic lesions in the body but are limited in their ability to detect microscopic lesions. Biomarker detection strategies are extremely sensitive and able to identify ng/ml concentrations of protein, but are poor at discriminating between healthy and disease state levels due to patient-to-patient variance, often leading to misdiagnosis. Gram negative bacteria, specifically Salmonella typhimurium and Escherichia coli, are potential anticancer agents because of their preferential accumulation and growth within tumors. This tumor specificity allows these bacteria to reduce off-target effects and it enables production of recombinant proteins directly at the tumor site. This thesis presents, three strategies for improving cancer therapy and detection using engineered bacteria

Trust Performance and Dramaturgical Plays in Virtual Teams

The paper uses the dramaturgical perspective for conceptualising trust development within temporary virtual teams. The underlying assumption is that temporary teams do not have the luxury of time, which according to the traditional trust theories, enables familiarity among project participants and promotes trust development. Yet, in these teams, trust needs to develop quickly and it is important that it lasts throughout the short duration of the project lifecycle. Using the metaphor of a theatre, the dramaturgical model of trust relationships is developed and is used to present actors, co-actors and audience as all playing a key role during the scripting, staging and performing phases of virtual plays. Particular importance is given to the interactions between these players at the performance stage. As it is argued, these interactions elicit the process of trust development within the temporary setting of virtual teams constituting to a type of trust relationship that is mutually negotiated and jointly constructed. This type of trust is called situated trust and emerges from the scripted and unscripted computer-mediated interactions of virtual players

What would Newly Qualified Teachers appointed in Cyprus Primary Schools expect from an effective school-based induction programme? Recommendations for the introduction of an effective school-based induction programme

This study investigates the induction of Newly Qualified Teachers (NQTs) in Cyprus Primary Education. In Cyprus, until September 2008, there was no formal induction policy for primary teachers. However, since June 2006, after the beginning of this study, the issue of inducting and evaluating NQTs has been extensively discussed in the context of the discussions about Educational Reform. The key purpose of the study was to make recommendations for the introduction of effective school-based induction activities/strategies for NQTs appointed in Cyprus Primary Education by identifying their needs and exploring their expectations of a school-based induction programme. The type of research approach selected was that of mixed methods research taking into account that it combined the use of both qualitative and quantitative research methods. The following data collecting instruments were used: a focus group interview with NQTs: postal questionnaires sent to NQTs: face to face interviews with NQTs; and e mail interviews with an NQT and the Minister of Education and Culture. The study used a national representative sample because its intention was to generalise the findings for the whole target population. According to the NQTs in my sample responses. NQTs appointed in Cyprus Primary Education are thrown in at the deep end, with a full teaching load and associated responsibilities with limited support. They also encounter many problems during the first years of teaching. Therefore, the NQTs argued that every school should implement an individual structured programme of support for all beginning teachers in order to help them overcome the specific problems they face. The induction programme must directly address NQTs' specific needs and concerns, must be flexible and should be negotiated on the basis of individual needs and goals. NQTs also underlined that the induction programme should serve several purposes and include many induction activities and opportunities of support. What they needed desperately was the presence of regular and structured guidance and support mainly from a mentor. In summary, based upon the findings, this study provides valuable information for determining which school-based strategies are likely to be useful and effective for Cyprus Primary NQTs

The pore system and engineering properties of hardened cement paste

The work described in this thesis is an attempt to elucidate the relationships between the pore system and a number of engineering properties of hardened cement paste, particularly tensile strength and resistances to carbonation and ionic penetration. By examining aspects such as the rate of carbonisation, the pore size distribution, the concentration of ions in the pore solution and the phase composition of cement pastes, relationships between the pore system (pores and pore solution) and the resistance to carbonation were investigated. The study was carried out in two parts. First, cement pastes with different pore systems were compared, whilst secondly comparisons were made between the pore systems of cement pastes with different degrees of carbonation. Relationships between the pore structure and ionic penetration were studied by comparing kinetic data relating to the diffusion of various ions in cement pastes with different pore systems. Diffusion coefficients and activation energies for the diffusion process of Cl- and Na+ ions in carbonated and non-carbonated cement pastes were determined by a quasi-steady state technique. The effect of the geometry of pores on ionic diffusion was studied by comparing the mechanisms of ionic diffusion for ions with different radii. In order to investigate the possible relationship between tensile strength and macroporosity, cement paste specimens with cross sectional areas less than 1mm2 were produced so that the chance of a macropore existing within them was low. The tensile strengths of such specimens were then compared with those of larger specimens

Chronic osteomyelitis: what the surgeon needs to know

Chronic osteomyelitis represents a progressive inflammatory process caused by pathogens, resulting in bone destruction and sequestrum formation. It may present with periods of quiescence of variable duration, whereas its occurrence, type, severity and prognosis is multifactorial. The ‘gold standard’ for the diagnosis of chronic osteomyelitis is the presence of positive bone cultures and histopathologic examination of the bone. Its management remains challenging to the treating physician, with a multidisciplinary approach involving radiologists, microbiologists with expertise in infectious diseases, orthopaedic surgeons and plastic surgeons. Treatment should be tailored to each patient according the severity and duration of symptoms, as well as to the clinical and radiological response to treatment. A combined antimicrobial and surgical treatment should be considered in all cases, including appropriate dead space management and subsequent reconstruction. Relapse can occur, even following an apparently successful treatment, which has a major impact on the quality of life of patients and is a substantial financial burden to any healthcare system

Bringing relevance to eLearning – a gender perspective

In this paper, we discuss the importance of relevance in the provision of eLearning for the pursuit of higher education (HE). In particular, we argue how the extant literature focuses on quality and security in the design of eLearning platforms, but pays scant attention to how relevant the platform and the programme contents are to the needs of contemporary adult learners. We studied this topic from a gender perspective and identified the different imperatives and constraints pertaining to men and women seeking personal and career development through HE. Recommendations are made for HE institutions to pay particular attention to the role that relevance plays in eLearning