A study of water binding, mobility and dehydration in contact lens hydrogels using NMR

Hydrogel polymers are used for the manufacture of soft (or disposable) contact lenses worldwide today, but have a tendency to dehydrate on the eye. In vitro methods that can probe the potential for a given hydrogel polymer to dehydrate in vivo are much sought after. Nuclear magnetic resonance (NMR) has been shown to be effective in characterising water mobility and binding in similar systems (Barbieri, Quaglia et al., 1998, Larsen, Huff et al., 1990, Peschier, Bouwstra et al., 1993), predominantly through measurement of the spin-lattice relaxation time (T1), the spinspin relaxation time (T2) and the water diffusion coefficient (D). The aim of this work was to use NMR to quantify the molecular behaviour of water in a series of commercially available contact lens hydrogels, and relate these measurements to the binding and mobility of the water, and ultimately the potential for the hydrogel to dehydrate. As a preliminary study, in vitro evaporation rates were measured for a set of commercial contact lens hydrogels. Following this, comprehensive measurement of the temperature and water content dependencies of T1, T2 and D was performed for a series of commercial hydrogels that spanned the spectrum of equilibrium water content (EWC) and common compositions of contact lenses that are manufactured today. To quantify material differences, the data were then modelled based on theory that had been used for similar systems in the literature (Walker, Balmer et al., 1989, Hills, Takacs et al., 1989). The differences were related to differences in water binding and mobility. The evaporative results suggested that the EWC of the material was important in determining a material's potential to dehydrate in this way. Similarly, the NMR water self-diffusion coefficient was also found to be largely (if not wholly) determined by the WC. A specific binding model confirmed that the we was the dominant factor in determining the diffusive behaviour, but also suggested that subtle differences existed between the materials used, based on their equilibrium we (EWC). However, an alternative modified free volume model suggested that only the current water content of the material was important in determining the diffusive behaviour, and not the equilibrium water content. It was shown that T2 relaxation was dominated by chemical exchange between water and exchangeable polymer protons for materials that contained exchangeable polymer protons. The data was analysed using a proton exchange model, and the results were again reasonably correlated with EWC. Specifically, it was found that the average water mobility increased with increasing EWe approaching that of free water. The T1 relaxation was also shown to be reasonably well described by the same model. The main conclusion that can be drawn from this work is that the hydrogel EWe is an important parameter, which largely determines the behaviour of water in the gel. Higher EWe results in a hydrogel with water that behaves more like bulk water on average, or is less strongly 'bound' on average, compared with a lower EWe material. Based on the set of materials used, significant differences due to composition (for materials of the same or similar water content) could not be found. Similar studies could be used in the future to highlight hydrogels that deviate significantly from this 'average' behaviour, and may therefore have the least/greatest potential to dehydrate on the eye.

"I'm a designer, get me out of tech class!" : closing the gap between design and technology education

The following paper explores the use of collaborative pedagogical approaches to advance foundational architectural design education, by linking design process to sustainable technology principles. After a brief discussion on architectural design education, the mentioned collaborative approach is described. This approach facilitates students’ exchange of knowledge between two courses, despite no explicit/assessable requirement to do so. The result for the students is deeper learning and a design process that is enriched through collaboration with sustainable technology. The success of this approach has been measured through questionnaires, evaluation surveys, and a comparative assessment of students common to both courses. The paper focuses on the challenges and innovations in connecting architectural design and technology education, where students are encouraged to implement lessons learnt, thereby closing the gap that these courses have traditionally represented.

Bridging the gap between tertiary education and work : a model of situated learning in accountancy

In professions such as teaching, health sciences (medicine, nursing, allied health), and built environment (engineering), significant work-based learning through practica is an essential element before graduation. However, there is no such requirement in Accountancy. This thesis reports the findings of a qualitative case study of the development and implementation of a Workplace Learning Experience Program in Accountancy at the Queensland University of Technology (QUT) in Australia. The case study of this intervention, based on sociocultural learning theory, provides the grounds for the development of a new model of teaching and learning for accounting education. The survey and interview-based study documents the responses of two cohorts of university students and a group of employers to a work placement program. The study demonstrates that a 100 hour work placement in Accountancy has elements that enhance student learning. It demonstrates the potential value of the application of sociocultural theories of learning, especially the concept of situated learning involving legitimate peripheral participation (Lave & Wenger, 1991). This research establishes the theoretical base for a paradigm shift for the Accountancy profession to acknowledge work placements prior to graduation as a major element of learning. It is argued that the current model of accounting education requires reform to better align university and workplace learning.

Closing the gap : the next steps for the interaction of corporate reputation and psychological contract development

With an increasing body of literature linking the human resource management and marketing fields, one area receiving increased academic attention is how an organisation’s corporate reputation can be managed to attract potential recruits and shape their employment expectations through their psychological contracts. This paper seeks to enhance current models which focus on the interrelationship of corporate reputation and psychological contract theory. It is argued that a number of factors need to be considered in order the build a firmer foundation for such a theory. Firstly, a common understanding of the psychological contract needs to be established such that the focus on either expectations or promises is clarified. Secondly, the included components of the psychological contract need to be considered in light of their empirical founding and their relationship with one another. Thirdly, the interrelationship of corporate reputation, employer branding, identity and image needs to be explicated within the context of how they both influence and interrelate with the psychological contract. The final consideration surrounds the opportunity for potential employees to be considered within the corporate reputation literature as a significant stakeholder group.

Visual field size criteria for mobility rehabilitation referral

Purpose. To investigate evidence-based visual field size criteria for referral of low-vision (LV) patients for mobility rehabilitation. Methods. One hundred and nine participants with LV and 41 age-matched participants with normal sight (NS) were recruited. The LV group was heterogeneous with diverse causes of visual impairment. We measured binocular kinetic visual fields with the Humphrey Field Analyzer and mobility performance on an obstacle-rich, indoor course. Mobility was assessed as percent preferred walking speed (PPWS) and number of obstacle-contact errors. The weighted kappa coefficient of association (κr) was used to discriminate LV participants with both unsafe and inefficient mobility from those with adequate mobility on the basis of their visual field size for the full sample and for subgroups according to type of visual field loss and whether or not the participants had previously received orientation and mobility training. Results. LV participants with both PPWS <38% and errors >6 on our course were classified as having inadequate (inefficient and unsafe) mobility compared with NS participants. Mobility appeared to be first compromised when the visual field was less than about 1.2 steradians (sr; solid angle of a circular visual field of about 70° diameter). Visual fields <0.23 and 0.63 sr (31 to 52° diameter) discriminated patients with at-risk mobility for the full sample and across the two subgroups. A visual field of 0.05 sr (15° diameter) discriminated those with critical mobility. Conclusions. Our study suggests that: practitioners should be alert to potential mobility difficulties when the visual field is less than about 1.2 sr (70° diameter); assessment for mobility rehabilitation may be warranted when the visual field is constricted to about 0.23 to 0.63 sr (31 to 52° diameter) depending on the nature of their visual field loss and previous history (at risk); and mobility rehabilitation should be conducted before the visual field is constricted to 0.05 sr (15° diameter; critical).

International students in Australian universities : gap between student expectations and realities

Australian Universities are very successful in attracting large number of international students. A large proportion of University revenue comes from the full fee paying international students. However, there have been many reports that international students face numerous problems when they arrive in Australia. The common management practice is to provide support staff services to deal with the orientation and welfare of international students. Such service units act as intermediaries between the students and the teaching and learning community of the university. However, the actual experience of international students may be difficult for support staff, counsellors, advisers and academic staff to anticipate. There is little information on the actual experience of students relative to their expectations. This study aimed at securing a deeper understanding of the contextually relevant issues facing by international students in Australian universities in order to develop management strategies aimed at improved teaching and learning outcomes for international students. Using a highly reliable survey questionnaire, a questionnaire survey was conducted among the international students at Queensland University of Technology (QUT), Brisbane, Australia. About 180 engineering students responded in the survey resulting in a response rate of 81%. Results indicate that international students face many difficulties including understanding colloquial language, Australian accent, cost of tuition, feelin isolation, safety, security, health services, accommodation and part time jobs. They also face difficulty in coping with learning methods in Australia, particularly in research report writing. However, they are happy with their lecturers and find them very helpful. Many of the students lacked the information regarding various community groups, recreational and sports facilities in Australia before arriving. Findings of the study show that there is a significant gap between the expectation of the students before coming to Australia and actual experience they experience here. Importantly, there is a lack of coordination between international students, international student services (ISS) and university management and as a consequence there have been little improvement in conditions. There is no direct link between student experience and University management. Many important suggestions arisen from this study and most important suggestion is that the student information system should be integrated with the University enterprise resource planning (ERP) to reduce the huge gap between international student expectation and actual experiences.

Wireless mobility usage: a preliminary study for management in two Australian university settings

Wireless Mobility Usage: A Preliminary Qualitative Study for Management in Two Australian University Settings, Neville Meyers, Heather Gray, Greg Hearn, Louis Sanzogni, and Sandra Lawrence.

Optimization problems for controlled mechanical systems : bridging the gap between theory and application

Mechanical control systems have become a part of our everyday life. Systems such as automobiles, robot manipulators, mobile robots, satellites, buildings with active vibration controllers and air conditioning systems, make life easier and safer, as well as help us explore the world we live in and exploit it’s available resources. In this chapter, we examine a specific example of a mechanical control system; the Autonomous Underwater Vehicle (AUV). Our contribution to the advancement of AUV research is in the area of guidance and control. We present innovative techniques to design and implement control strategies that consider the optimization of time and/or energy consumption. Recent advances in robotics, control theory, portable energy sources and automation increase our ability to create more intelligent robots, and allows us to conduct more explorations by use of autonomous vehicles. This facilitates access to higher risk areas, longer time underwater, and more efficient exploration as compared to human occupied vehicles. The use of underwater vehicles is expanding in every area of ocean science. Such vehicles are used by oceanographers, archaeologists, geologists, ocean engineers, and many others. These vehicles are designed to be agile, versatile and robust, and thus, their usage has gone from novelty to necessity for any ocean expedition.

Occupational mobility in Queensland’s aged care, automotive and civil construction sectors

Current trends in workforce development indicate the movement of workers within and across occupations to be the norm. In 2009, only one in three vocational education and training (VET) graduates in Australia ended up working in an occupation for which they were trained. This implies that VET enhances the employability of its graduates by equipping them with the knowledge and competencies to work in different occupations and sectors. This paper presents findings from a Government-funded study that examined the occupational mobility of selected associate professional and trades occupations within the Aged Care, Automotive and Civil Construction sectors in Queensland. The study surveyed enrolled nurses and related workers, motor mechanics and civil construction workers to analyse their patterns of occupational mobility, future work intentions, reasons for taking and leaving work, and the factors influencing them to leave or remain in their occupations. This paper also discusses the implications of findings for the training of workers in these sectors and more generally.

Constitutional legitimacy : an international ill and gap in the literature?

The central argument of this work is that “democratic constitutional legitimacy”[2] probably does not currently exist in the politics of any country internationally. This inherent problem in constitutionalism is an endemic governance problem most citizenries should be dealing with, only that we are not in a large extent doing so and haven’t been historically. This position was ascertained using a form of Beck and Grande’s (2010) cosmopolitan methodology in my doctoral thesis (which we shall return to). It is argued that every constitution is in need of considerable rethinking so as to bring its statutes in line with the interests of the plurality of individuals it oversees. Finally, this work attempts to show that research in this area of democratic constitutional legitimacy is lacking in the literature as only a few scholars presently engage the issue (namely Simone Chambers).

Policing lesbian, gay, bisexual and transgender young people : a gap in the research literature

This article argues for exploring lesbian, gay, bisexual, and transgender (LGBT) young people’s experiences with police. While research examines how factors such as indigeneity influence young peoples’ experiences with police, how sexuality and/or gender identity mediates these relationships remains largely unexplored. Key bodies of research suggest a need to explore this area further, including: literature documenting links between homophobic violence against LGBT young people and outcomes such as homelessness that fall within the gambit of policing work; research showing reluctance of LGBT communities to report crime to police; international research documenting homophobic police attitudes and Australian research demonstrating arguably homophobic court outcomes; and research outlining increasing police support of LGBT communities. Drawing on these bodies of literature, this article argues that LGBT young people experience policing warrants further research.

A sense of control : virtual communities for people with mobility impairments

The purpose of this book is to show why we should be concerned about virtual communities for people with physical, or more particularly mobility, impairments. The well-being model through a virtual community introduced here goes towards advancing the work begun by others, by adding for example a socio-political component. The model presented here provides practical insights into how strategic community investment can support people with disabilities and their families. Virtual communities are about engagement, quality of life and support, not just about information. The role of information technology in building and raising community capacity and social capital in socially and economically disadvantaged communities is also examined. Practical insights are offered into community support for people with chronic illness.

Mobility, accessibility and activity participation : a comparative assessment of methods to identify rural transport disadvantage

Traditionally, transport disadvantage has been identified using accessibility analysis although the effectiveness of the accessibility planning approach to improving access to goods and services is not known. This paper undertakes a comparative assessment of measures of mobility, accessibility, and participation used to identify transport disadvantage using the concept of activity spaces. A 7 day activity-travel diary data for 89 individuals was collected from two case study areas located in rural Northern Ireland. A spatial analysis was conducted to select the case study areas using criteria derived from the literature. The criteria are related to the levels of area accessibility and area mobility which are known to influence the nature of transport disadvantage. Using the activity-travel diary data individuals weekly as well as day to day variations in activity-travel patterns were visualised. A model was developed using the ArcGIS ModelBuilder tool and was run to derive scores related to individual levels of mobility, accessibility, and participation in activities from the geovisualisation. Using these scores a multiple regression analysis was conducted to identify patterns of transport disadvantage. This study found a positive association between mobility and accessibility, between mobility and participation, and between accessibility and participation in activities. However, area accessibility and area mobility were found to have little impact on individual mobility, accessibility, and participation in activities. Income vis-àvis ´ car-ownership was found to have a significant impact on individual levels of mobility, and accessibility; whereas participation in activities were found to be a function of individual levels of income and their occupational status.