Cellular senescence and longevity of osteophyte-derived mesenchymal stem cells compared to patient-matched bone marrow stromal cells

This study aimed to determine the cellular aging of osteophyte-derived mesenchymal cells (oMSCs) in comparison to patient-matched bone marrow stromal cells (bMSCs). Extensive expansion of the cell cultures was performed and early and late passage cells (passages 4 and 9, respectively) were used to study signs of cellular aging, telomere length, telomerase activity, and cell-cycle-related gene expression. Our results showed that cellular aging was more prominent in bMSCs than in oMSCs, and that oMSCs had longer telomere length in late passages compared with bMSCs, although there was no significant difference in telomere lengths in the early passages in either cell type. Telomerase activity was detectable only in early passage oMSCs and not in bMSCs. In osteophyte tissues telomerase-positive cells were found to be located perivascularly and were Stro-1 positive. Fifteen cell-cycle regulator genes were investigated and only three genes (APC, CCND2, and BMP2) were differentially expressed between bMSC and oMSC. Our results indicate that oMSCs retain a level of telomerase activity in vitro, which may account for the relatively greater longevity of these cells, compared with bMSCs, by preventing replicative senescence. J. Cell. Biochem. 108: 839-850, 2009. (c) 2009 Wiley-Liss, Inc.

Sustainable urban futures : an ecological approach to sustainable urban development

In recent years, cities show increasing signs of environmental problems due to the negative impacts of urban activities. The degradation and depletion of natural resources, climate change and development pressure on green areas have become major concerns for cities. In response to these problems, urban planning policies have shifted to a sustainable focus and authorities have begun to develop new strategies for improving the quality of urban ecosystems. An extremely important function of an urban ecosystem is to provide healthy and sustainable environments for both natural systems and communities. Therefore, ecological planning is a functional requirement in the establishment of sustainable built environment. With ecological planning human needs are supplied while natural resources are used in the most effective and sustainable manner. And the maintenance of ecological balance is sustained. Protecting human and environmental health, having healthy ecosystems, reducing environmental pollution and providing green spaces are just a few of the many benefits of ecological planning. In this context, the paper briefly presents a short overview of the importance of the implementation of ecological planning into sustainable urban development. Furthermore, the paper defines the conceptual framework of a new method for developing sustainable urban ecosystems through ecological planning approach. In the future of the research, this model will be developed as a guideline for the assessment of the ecological sustainability in built environments.

Factors related to the presentation of thin and thick nodular melanoma from a population-based cancer registry in Queensland Australia

Purpose: Worldwide, the incidence of thick melanoma has not declined, and the nodular melanoma (NM) subtype accounts for nearly 40% of newly-diagnosed thick melanoma. To assess differences between patients with thin (≤2.00 mm) and thick (≥2.01 mm) nodular melanoma, we evaluated factors such as demographics, melanoma detection patterns, tumor visibility, and physician screening for NM alone and compared clinical presentation and anatomic location of NM with superficial spreading melanoma (SSM). Methods We utilized data from a large population-based study of Queensland (Australia) residents diagnosed with melanoma. Queensland residents aged 20 to 75 years with histologically confirmed first primary invasive cutaneous melanoma were eligible for the study, and all questionnaires were conducted by telephone (response rate 77.9%). Results During this four-year period, 369 patients with nodular melanoma were interviewed, of whom 56.7% were diagnosed with tumors ≤ 2.00 mm. Men, older individuals, and those who had not been screened by a physician in the past three years were more likely to have nodular tumors of greater thickness. Thickest nodular melanoma (4 mm+) was also most common in persons who had not been screened by a doctor within the past three years (OR 3.75; 95% CI 1.47-9.59). Forty-six percent of patients with thin nodular melanoma (≤ 2.00 mm) reported a change in color, compared with 64% of patients with thin SSM and 26% of patients with thick nodular melanoma (>2.00 mm). Conclusion Awareness of factors related to earlier detection of potentially fatal nodular melanomas, including the benefits of a physician examination, should be useful in enhancing public and professional education strategies. Particular awareness of clinical warning signs associated with thin nodular melanoma should allow for more prompt diagnosis and treatment of this subtype.

Hell-vetica

Helvetica (connotes Swiss typeface) has been used the most widely from street signs to government campaign posters since 1957. Helvetica represents a great leap forward for modernity: clean, sans-serif, optimistic. However in history, there was a movement against Helvetica among American artists and designers since David Carson and Paula Scher indicted Helvetica as the cause of Vietnam war. Paradoxically, we celebrated its 50th birthday in 2007. Helvetica’s message it this: “you are going to get to your destination on time; your plan will not crash; your money is safe in our vault; we will not break the package; the paperwork has been filled in; everything is going to be OK” (Finlo Rohrer, Helvetica At 50, BBC News Magazine 9 May 2007). The artwork, Hell-vetica describes its characteristic of double agent for modernism and postmodernism in this contemporary era by combination of a stylised graphical form of a heart shape in red and a typographical manipulation - Hell-vetica.

Three-dimensional reconstruction of an ancient Egyptian mummy

A complete series of cross-sectional computed tomography (CT) scans were obtained of a mummy of an Egyptian priestess, Tjenmutengebtiu, (Jeni), who lived in the twenty-second Dynasty (c. 945-715 BC). The purpose of this joint British Museum and St. Thomas’ Hospital project was effectively to ‘unwrap’ a mummy using cross-sectional X-rays. Jeni is encased in a beautifully decorated anthropomorphic cartonnage coffin. The head and neck were scanned with 2mm slices, the teeth with 1mm slices and the rest of the body with 4 mm slices, a 512 x 512 matrix was used. The 2D CT images, and 3D surface reconstruction’s, demonstrate many features of the embalming techniques and funerary customs of the XXII Dynasty. The presence of cloth protruding from the nasal cavities into the otherwise empty cranial cavity indicates that the brain was extracted via the nose. The remains of the heart can be seen as well as four organ packs corresponding to the mummified and repackaged lungs, intestines, stomach and liver. Each of the organ packs encloses a wax figurine representing one of the four sons of Horus. The teeth are in very good condition with little signs of wear, which, considering the gritty diet of the Egyptians, indicates that Jeni must have been very young when she died. A young age of death is also suggested by analysis of the shape of the molar teeth. The body is generally in very good condition demonstrating the consummate skill of the twenty-second Dynasty embalmers.

Learning in the third space : a sociocultural perspective on learning with analogies

Research on analogies in science education has focussed on student interpretation of teacher and textbook analogies, psychological aspects of learning with analogies and structured approaches for teaching with analogies. Few studies have investigated how analogies might be pivotal in students’ growing participation in chemical discourse. To study analogies in this way requires a sociocultural perspective on learning that focuses on ways in which language, signs, symbols and practices mediate participation in chemical discourse. This study reports research findings from a teacher-research study of two analogy-writing activities in a chemistry class. The study began with a theoretical model, Third Space, which informed analyses and interpretation of data. Third Space was operationalized into two sub-constructs called Dialogical Interactions and Hybrid Discourses. The aims of this study were to investigate sociocultural aspects of learning chemistry with analogies in order to identify classroom activities where students generate Dialogical Interactions and Hybrid Discourses, and to refine the operationalization of Third Space. These aims were addressed through three research questions. The research questions were studied through an instrumental case study design. The study was conducted in my Year 11 chemistry class at City State High School for the duration of one Semester. Data were generated through a range of data collection methods and analysed through discourse analysis using the Dialogical Interactions and Hybrid Discourse sub-constructs as coding categories. Results indicated that student interactions differed between analogical activities and mathematical problem-solving activities. Specifically, students drew on discourses other than school chemical discourse to construct analogies and their growing participation in chemical discourse was tracked using the Third Space model as an interpretive lens. Results of this study led to modification of the theoretical model adopted at the beginning of the study to a new model called Merged Discourse. Merged Discourse represents the mutual relationship that formed during analogical activities between the Analog Discourse and the Target Discourse. This model can be used for interpreting and analysing classroom discourse centred on analogical activities from sociocultural perspectives. That is, it can be used to code classroom discourse to reveal students’ growing participation with chemical (or scientific) discourse consistent with sociocultural perspectives on learning.

Translation and news making : a study of contemporary arabic television

Arabic satellite television has recently attracted tremendous attention in both the academic and professional worlds, with a special interest in Aljazeera as a curious phenomenon in the Arab region. Having made a household name for itself worldwide with the airing of the Bin Laden tapes, Aljazeera has set out to deliberately change the culture of Arabic journalism, as it has been repeatedly stated by its current General Manager Waddah Khanfar, and to shake up the Arab society by raising awareness to issues never discussed on television before and challenging long-established social and cultural values and norms while promoting, as it claims, Arab issues from a presumably Arab perspective. Working within the meta-frame of democracy, this Qatari-based network station has been received with mixed reactions ranging from complete support to utter rejection in both the west and the Arab world. This research examines the social semiotics of Arabic television and the socio-cultural impact of translation-mediated news in Arabic satellite television, with the aim to carry out a qualitative content analysis, informed by framing theory, critical linguistic analysis, social semiotics and translation theory, within a re-mediation framework which rests on the assumption that a medium “appropriates the techniques, forms and social significance of other media and attempts to rival or refashion them in the name of the real" (Bolter and Grusin, 2000: 66). This is a multilayered research into how translation operates at two different yet interwoven levels: translation proper, that is the rendition of discourse from one language into another at the text level, and translation as a broader process of interpretation of social behaviour that is driven by linguistic and cultural forms of another medium resulting in new social signs generated from source meaning reproduced as target meaning that is bound to be different in many respects. The research primarily focuses on the news media, news making and reporting at Arabic satellite television and looks at translation as a reframing process of news stories in terms of content and cultural values. This notion is based on the premise that by its very nature, news reporting is a framing process, which involves a reconstruction of reality into actualities in presenting the news and providing the context for it. In other words, the mediation of perceived reality through a media form, such as television, actually modifies the mind’s ordering and internal representation of the reality that is presented. The research examines the process of reframing through translation news already framed or actualized in another language and argues that in submitting framed news reports to the translation process several alterations take place, driven by the linguistic and cultural constraints and shaped by the context in which the content is presented. These alterations, which involve recontextualizations, may be intentional or unintentional, motivated or unmotivated. Generally, they are the product of lack of awareness of the dynamics and intricacies of turning a message from one language form into another. More specifically, they are the result of a synthesis process that consciously or subconsciously conforms to editorial policy and cultural interpretive frameworks. In either case, the original message is reproduced and the news is reframed. For the case study, this research examines news broadcasts by the now world-renowned Arabic satellite television station Aljazeera, and to a lesser extent the Lebanese Broadcasting Corporation (LBC) and Al- Arabiya where access is feasible, for comparison and crosschecking purposes. As a new phenomenon in the Arab world, Arabic satellite television, especially 24-hour news and current affairs, provides an interesting area worthy of study, not only for its immediate socio-cultural and professional and ethical implications for the Arabic media in particular, but also for news and current affairs production in the western media that rely on foreign language sources and translation mediation for international stories.

Introducing a Business Process and Software Centric Approach for Enterprise System Teaching

To meet new challenges of Enterprise Systems that essentially go beyond the initial implementation, contemporary organizations seek employees with business process experts with software skills. Despite a healthy demand from the industry for such expertise, recent studies reveal that most Information Systems (IS) graduates are ill-equipped to meet the challenges of modern organizations. This paper shares insights and experiences from a course that is designed to provide a business process centric view of a market leading Enterprise System. The course, designed for both undergraduate and graduate students, uses two common business processes in a case study that employs both sequential and explorative exercises. Student feedback gained through two longitudinal surveys across two phases of the course demonstrates promising signs of the teaching approach.

Unilateral pseudogerontoxon

Peripheral corneal opacities are a common clinical finding. In this case report we describe the routine presentation of a young adult male patient with unilateral opacities in the peripheral cornea resembling a corneal arcus. These opacities were confined to the level of the anterior corneal stroma. The patient also exhibited bilateral signs of mild keratoconus and reported a history of vernal keratoconjunctivitis as a child. A diagnosis of unilateral pseudogerontoxon was made. Pseudogerontoxon is an opacity of the peripheral cornea resembling corneal arcus that typically occurs in patients with a history of allergic eye disease. The clinical features and differential diagnoses of this relatively uncommon cause of peripheral corneal opacity are discussed.

Characterisation of mesenchymal cells from osteophytes in osteoarthritis

Osteophytes form through the process of chondroid metamorphosis of fibrous tissue followed by endochondral ossification. Osteophytes have been found to consist of three different mesenchymal tissue regions including endochondral bone formation within cartilage residues, intra-membranous bone formation within fibrous tissue and bone formation within bone marrow spaces. All these features provide evidence of mesenchymal stem cells (MSC) involvement in osteophyte formation; nevertheless, it remains to be characterised. MSC from numerous mesenchymal tissues have been isolated but bone marrow remains the “ideal” due to the ease of ex vivo expansion and multilineage potential. However, the bone marrow stroma has a relatively low number of MSC, something that necessitates the need for long-term culture and extensive population doublings in order to obtain a sufficient number of cells for therapeutic applications. MSC in vitro have limited proliferative capacity and extensive passaging compromises differentiation potential. To overcome this barrier, tissue derived MSC are of strong interest for extensive study and characterisation, with a focus on their potential application in therapeutic tissue regeneration. To date, no MSC type cell has been isolated from osteophyte tissue, despite this tissue exhibiting all the hallmark features of a regenerative tissue. Therefore, this study aimed to isolate and characterise cells from osteophyte tissues in relation to their phenotype, differentiation potential, immuno-modulatory properties, proliferation, cellular ageing, longevity and chondrogenesis in in vitro defect model in comparison to patient matched bone marrow stromal cells (bMSC). Osteophyte derived cells were isolated from osteophyte tissue samples collected during knee replacement surgery. These cells were characterised by the expression of cell surface antigens, differentiation potential into mesenchymal lineages, growth kinetics and modulation of allo-immune responses. Multipotential stem cells were identified from all osteophyte samples namely osteophyte derived mesenchymal stem cells (oMSC). Extensively expanded cell cultures (passage 4 and 9 respectively) were used to confirm cytogenetic stability and study signs of cellular aging, telomere length and telomerase activity. Cultured cells at passage 4 were used to determine 84 pathway focused stem cell related gene expression profile. Micro mass pellets were cultured in chondrogenic differentiation media for 21 days for phenotypic and chondrogenic related gene expression. Secondly, cell pellets differentiated overnight were placed into articular cartilage defects and cultured for further 21 days in control medium and chondrogenic medium to study chondrogenesis and cell behaviour. The surface antigen expression of oMSC was consistent with that of mesenchymal stem cells, such as lacking the haematopoietic and common leukocyte markers (CD34, CD45) while expressing those related to adhesion (CD29, CD166, CD44) and stem cells (CD90, CD105, CD73). The proliferation capacity of oMSC in culture was superior to that of bMSC, and they readily differentiated into tissues of the mesenchymal lineages. oMSC also demonstrated the ability to suppress allogeneic T-cell proliferation, which was associated with the expression of tryptophan degrading enzyme indoleamine 2,3 dioxygenase (IDO). Cellular aging was more prominent in late passage bMSC than in oMSC. oMSC had longer telomere length in late passages compared with bMSC, although there was no significant difference in telomere lengths in the early passages in either cell type. Telomerase activity was detectable only in early passage oMSC and not in bMSC. In osteophyte tissues telomerase positive cells were found to be located peri vascularly and were Stro-1 positive. Eighty-four pathway-focused genes were investigated and only five genes (APC, CCND2, GJB2, NCAM and BMP2) were differentially expressed between bMSC and oMSC. Chondrogenically induced micro mass pellets of oMSC showed higher staining intensity for proteoglycans, aggrecan and collagen II. Differential expression of chondrogenic related genes showed up regulation of Aggrecan and Sox 9 in oMSC and collagen II in bMSC. The in vitro defect models of oMSC in control medium showed rounded and aggregated cells staining positively for proteoglycan and presence of some extracellular matrix. In contrast, defects with bMSC showed fragmentation and loss of cells, fibroblast-like cell morphology staining positively for proteoglycans. For defects maintained in chondrogenic medium, rounded, aggregated and proteoglycan positive cells were found in both oMSC and bMSC cultures. Extracellular matrix and cellular integration into newly formed matrix was evident only in oMSC defects. For analysis of chondrocyte hypertrophy, strong expression of type X collagen could be noticed in the pellet cultures and transplanted bMSC. In summary, this study demonstrated that osteophyte derived cells had similar properties to mesenchymal stem cells in the expression of antigen phenotype, differential potential and suppression of allo-immune response. Furthermore, when compared to bMSC, oMSC maintained a higher proliferative capacity due to a retained level of telomerase activity in vitro, which may account for the relatively longer telomeres delaying growth arrest by replicative senescence compared with bMSC. oMSC behaviour in defects supported chondrogenesis which implies that cells derived from regenerative tissue can be an alternative source of stem cells and have a potential clinical application for therapeutic stem cell based tissue regeneration.

Reempowering ourselves: Australian Aboriginal women

The arrival of the colonists, the invasion of Aboriginal lands and the subsequent colonization of Australia had a disastrous effect on Aboriginal women, including on-going dispossession and disempowerment. Aboriginal women’s lives and gendered realities were forever changed in most communities. The system of colonization deprived Aboriginal women of land and personal autonomy and restricted the economic, political, social, spiritual and ceremonial domains that had existed prior to colonization. It also involved the implementation of overriding patriarchal systems. This is why Aboriginal women may find understanding within the women’s movement and why feminism might offer them a source of analysis. There are some connections in the various forms of social oppression, which give women connection and a sharing on some issues. However, imperialism and colonialism are also part of the women’s movement and feminism. This essay demonstrates why attempts to engage with feminism and to be included in women-centred activities might result in the denial and sidelining of Aboriginal sovereignty and further oppression and marginalisation of Aboriginal women. Moreover, strategies employed by non-Indigenous feminists can result in the maintenance of white women’s values and privileges within the dominant patriarchal white society. By engaging in these strategies feminists can also act in direct opposition to Aboriginal sovereignty and Aboriginal women. This essay states clearly that women who do not express positions or opinions in outright support of these activities still benefit from their position by proxy and contribute to the cultural dominance of non-Indigenous women. I argue that Aboriginal women need to define what empowerment might mean to themselves, and I suggest re-empowerment as an act of Aboriginal women’s healing and resistance to the on-going processes and impacts of colonization.

Queensland Aborigines, multiple realities and the social sources of suffering: Psychiatry and moral regions of being (Part 1)

This two part paper considers the experience of a range of magico-religious experiences (such as visions and voices) and spirit beliefs in a rural Aboriginal town. The papers challenge the tendency of institutionalised psychiatry to medicalise the experiences and critiques the way in which its individualistic practice is intensified in the face of an incomprehensible Aboriginal „other‟ to become part of the power imbalance that characterises the relationship between Indigenous and white domains. The work reveals the internal differentiation and politics of the Aboriginal domain, as the meanings of these experiences and actions are contested and negotiated by the residents and in so doing they decentre the concerns of the white domain and attempt to control their relationship with it. Thus the plausibility structure that sustains these multiple realities reflects both accommodation and resistance to the material and historical conditions imposed and enacted by mainstream society on the residents, and to current socio- political realities. I conclude that the residents‟ narratives chart the grounds of moral adjudication as the experiences were rarely conceptualised by local people as signs of individual pathology but as reflections of social reality. Psychiatric drug therapy and the behaviourist assumptions underlying its practice posit atomised individuals as the appropriate site of intervention as against the multiple realities revealed by the phenomenology of the experiences. The papers thus call into question Australian mainstream „commonsense‟ that circulates about Aboriginal and Torres Strait Islander people which justifies representations of them as sickly outcasts in Australian society.

Using honeypots to analyse anomalous Internet activities

Monitoring Internet traffic is critical in order to acquire a good understanding of threats to computer and network security and in designing efficient computer security systems. Researchers and network administrators have applied several approaches to monitoring traffic for malicious content. These techniques include monitoring network components, aggregating IDS alerts, and monitoring unused IP address spaces. Another method for monitoring and analyzing malicious traffic, which has been widely tried and accepted, is the use of honeypots. Honeypots are very valuable security resources for gathering artefacts associated with a variety of Internet attack activities. As honeypots run no production services, any contact with them is considered potentially malicious or suspicious by definition. This unique characteristic of the honeypot reduces the amount of collected traffic and makes it a more valuable source of information than other existing techniques. Currently, there is insufficient research in the honeypot data analysis field. To date, most of the work on honeypots has been devoted to the design of new honeypots or optimizing the current ones. Approaches for analyzing data collected from honeypots, especially low-interaction honeypots, are presently immature, while analysis techniques are manual and focus mainly on identifying existing attacks. This research addresses the need for developing more advanced techniques for analyzing Internet traffic data collected from low-interaction honeypots. We believe that characterizing honeypot traffic will improve the security of networks and, if the honeypot data is handled in time, give early signs of new vulnerabilities or breakouts of new automated malicious codes, such as worms. The outcomes of this research include: • Identification of repeated use of attack tools and attack processes through grouping activities that exhibit similar packet inter-arrival time distributions using the cliquing algorithm; • Application of principal component analysis to detect the structure of attackers’ activities present in low-interaction honeypots and to visualize attackers’ behaviors; • Detection of new attacks in low-interaction honeypot traffic through the use of the principal component’s residual space and the square prediction error statistic; • Real-time detection of new attacks using recursive principal component analysis; • A proof of concept implementation for honeypot traffic analysis and real time monitoring.

The impact of presbyopic spectacles and contact lenses on driving performance

Presbyopia affects individuals from the age of 45 years onwards, resulting in difficulty in accurately focusing on near objects. There are many optical corrections available including spectacles or contact lenses that are designed to enable presbyopes to see clearly at both far and near distances. However, presbyopic vision corrections also disturb aspects of visual function under certain circumstances. The impact of these changes on activities of daily living such as driving are, however, poorly understood. Therefore, the aim of this study was to determine which aspects of driving performance might be affected by wearing different types of presbyopic vision corrections. In order to achieve this aim, three experiments were undertaken. The first experiment involved administration of a questionnaire to compare the subjective driving difficulties experienced when wearing a range of common presbyopic contact lens and spectacle corrections. The questionnaire was developed and piloted, and included a series of items regarding difficulties experienced while driving under day and night-time conditions. Two hundred and fifty five presbyopic patients responded to the questionnaire and were categorised into five groups, including those wearing no vision correction for driving (n = 50), bifocal spectacles (BIF, n = 54), progressive addition lenses spectacles (PAL, n = 50), monovision (MV, n = 53) and multifocal contact lenses (MTF CL, n = 48). Overall, ratings of satisfaction during daytime driving were relatively high for all correction types. However, MV and MTF CL wearers were significantly less satisfied with aspects of their vision during night-time than daytime driving, particularly with regard to disturbances from glare and haloes. Progressive addition lens wearers noticed more distortion of peripheral vision, while BIF wearers reported more difficulties with tasks requiring changes in focus and those who wore no vision correction for driving reported problems with intermediate and near tasks. Overall, the mean level of satisfaction for daytime driving was quite high for all of the groups (over 80%), with the BIF wearers being the least satisfied with their vision for driving. Conversely, at night, MTF CL wearers expressed the least satisfaction. Research into eye and head movements has become increasingly of interest in driving research as it provides a means of understanding how the driver responds to visual stimuli in traffic. Previous studies have found that wearing PAL can affect eye and head movement performance resulting in slower eye movement velocities and longer times to stabilize the gaze for fixation. These changes in eye and head movement patterns may have implications for driving safety, given that the visual tasks for driving include a range of dynamic search tasks. Therefore, the second study was designed to investigate the influence of different presbyopic corrections on driving-related eye and head movements under standardized laboratory-based conditions. Twenty presbyopes (mean age: 56.1 ± 5.7 years) who had no experience of wearing presbyopic vision corrections, apart from single vision reading spectacles, were recruited. Each participant wore five different types of vision correction: single vision distance lenses (SV), PAL, BIF, MV and MTF CL. For each visual condition, participants were required to view videotape recordings of traffic scenes, track a reference vehicle and identify a series of peripherally presented targets while their eye and head movements were recorded using the faceLAB® eye and head tracking system. Digital numerical display panels were also included as near visual stimuli (simulating the visual displays of a vehicle speedometer and radio). The results demonstrated that the path length of eye movements while viewing and responding to driving-related traffic scenes was significantly longer when wearing BIF and PAL than MV and MTF CL. The path length of head movements was greater with SV, BIF and PAL than MV and MTF CL. Target recognition was less accurate when the near stimulus was located at eccentricities inferiorly and to the left, rather than directly below the primary position of gaze, regardless of vision correction type. The third experiment aimed to investigate the real world driving performance of presbyopes while wearing different vision corrections measured on a closed-road circuit at night-time. Eye movements were recorded using the ASL Mobile Eye, eye tracking system (as the faceLAB® system proved to be impractical for use outside of the laboratory). Eleven participants (mean age: 57.25 ± 5.78 years) were fitted with four types of prescribed vision corrections (SV, PAL, MV and MTF CL). The measures of driving performance on the closed-road circuit included distance to sign recognition, near target recognition, peripheral light-emitting-diode (LED) recognition, low contrast road hazards recognition and avoidance, recognition of all the road signs, time to complete the course, and driving behaviours such as braking, accelerating, and cornering. The results demonstrated that driving performance at night was most affected by MTF CL compared to PAL, resulting in shorter distances to read signs, slower driving speeds, and longer times spent fixating road signs. Monovision resulted in worse performance in the task of distance to read a signs compared to SV and PAL. The SV condition resulted in significantly more errors made in interpreting information from in-vehicle devices, despite spending longer time fixating on these devices. Progressive addition lenses were ranked as the most preferred vision correction, while MTF CL were the least preferred vision correction for night-time driving. This thesis addressed the research question of how presbyopic vision corrections affect driving performance and the results of the three experiments demonstrated that the different types of presbyopic vision corrections (e.g. BIF, PAL, MV and MTF CL) can affect driving performance in different ways. Distance-related driving tasks showed reduced performance with MV and MTF CL, while tasks which involved viewing in-vehicle devices were significantly hampered by wearing SV corrections. Wearing spectacles such as SV, BIF and PAL induced greater eye and head movements in the simulated driving condition, however this did not directly translate to impaired performance on the closed- road circuit tasks. These findings are important for understanding the influence of presbyopic vision corrections on vision under real world driving conditions. They will also assist the eye care practitioner to understand and convey to patients the potential driving difficulties associated with wearing certain types of presbyopic vision corrections and accordingly to support them in the process of matching patients to optical corrections which meet their visual needs.

Peripheral higher order aberrations in emmetropes and myopes

Purpose: Poor image quality in the peripheral field may lead to myopia. Most studies measuring the higher order aberrations in the periphery have been restricted to the horizontal visual field. The purpose of this study was to measure higher order monochromatic aberrations across the central 42º horizontal x 32º vertical visual fields in myopes and emmetropes. ---------- Methods: We recruited 5 young emmetropes with spherical equivalent refractions +0.17 ± 0.45D and 5 young myopes with spherical equivalent refractions -3.9 ± 2.09D. Measurements were taken with a modified COAS-HD Hartmann-Shack aberrometer (Wavefront Sciences Inc). Measurements were taken while the subjects looked at 38 points arranged in a 7 x 6 matrix (excluding four corner points) through a beam splitter held between the instrument and the eye. A combination of the instrument’s software and our own software was used to estimate OSA Zernike coefficients for 5mm pupil diameter at 555nm for each point. The software took into account the elliptical shape of the off-axis pupil. Nasal and superior fields were taken to have positive x and y signs, respectively. ---------- Results: The total higher order RMS (HORMS) was similar on-axis for emmetropes (0.16 ± 0.02 μm) and myopes (0.17 ± 0.02 μm). There was no common pattern for HORMS for emmetropes across the visual field where as 4 out of 5 myopes showed a linear increase in HORMS in all directions away from the minimum. For all subjects, vertical and horizontal comas showed linear changes across the visual field. The mean rate of change of vertical coma across the vertical meridian was significantly lower (p = 0.008) for emmetropes (-0.005 ± 0.002 μm/deg) than for myopes (-0.013 ± 0.004 μm/deg). The mean rate of change of horizontal coma across the horizontal meridian was lower (p = 0.07) for emmetropes (-0.006 ± 0.003 μm/deg) than myopes (-0.011 ± 0.004 μm/deg). ---------- Conclusion: We have found differences in patterns of higher order aberrations across the visual fields of emmetropes and myopes, with myopes showing the greater rates of change of horizontal and vertical coma.