The effect of monocular and binocular cataract blur on postural stability among older adults

Purpose: First-eye cataract surgery can reduce the rate of falls among older adults, yet the effect of second-eye surgery on the rate of falling remains unclear. The present study investigated the effect of monocular and binocular simulated cataract blur on postural stability among older adults. Methods: Postural stability was assessed on 34 healthy older adults (mean 68.2 years, SD 3.5) with normal vision, using a portable force platform (BT4, HUR Labs, Finland) which collected data on centre of pressure (COP) displacement. Stability was assessed on firm and foam surfaces under four binocular viewing conditions using Vistech filters to simulate cataract blur: [1] best-corrected vision both eyes; [2] blur over non-dominant eye, [3] blur over dominant eye and [4] blur over both eyes. Binocular logMAR visual acuity, Pelli-Robson contrast sensitivity and stereoacuity were also measured under these viewing conditions and ocular dominance measured using the hole-in-card test. Generalized estimating equations with an exchangeable correlation structure examined the effect of the surface and vision conditions on postural stability. Results: Visual acuity and contrast sensitivity were significantly reduced under monocular and binocular cataract blur compared to normal viewing. All blur conditions resulted in loss of stereoacuity. Binocular cataract blur significantly reduced postural stability compared to normal vision on the firm (COP path length; p=0.013) and foam surface (anterior-posterior COP RMS, COP path length and COP area; p<0.01). However, no significant differences in postural stability were found between the monocular blur conditions compared to normal vision, or between the dominant and non-dominant monocular blur conditions on either the firm or foam surfaces. Conclusions: Findings indicate that binocular blur significantly impairs postural stability, and suggests that improvements in postural stability may justify first-eye cataract surgery, particularly during somatosensory disruption. Postural stability was not significantly impaired in the monocular cataract blur conditions compared to the normal vision condition, nor was there any effect of ocular dominance on postural stability in the presence of monocular cataract blur.

How Australia’s Indigenous people are positioned within health service sites by our presence and by our absence

De Certeau (1984) constructs the notion of belonging as a sentiment which develops over time through the everyday activities. He explains that simple everyday activities are part of the process of appropriation and territorialisation and suggests that over time belonging and attachment are established and built on memory, knowledge and the experiences of everyday activities. Based on the work of de Certeau, non-Indigenous Australians have developed attachment and belonging to places based on the dispossession of Aboriginal people and on their everyday practices over the past two hundred years. During this time non-Indigenous people have marked their appropriation and territorialisation with signs, symbols, representations and images. In marking their attachment, they also define how they position Australia’s Indigenous people by both our presence and our absence. This paper will explore signs and symbols within spaces and places in health services and showcase how they reflect the historical, political, cultural, social and economic values, and power relations of broader society. It will draw on the voices of Aboriginal women to demonstrate their everyday experiences of such sites. It will conclude by highlighting how Aboriginal people assert their identities and un-ceded sovereignty within such health sites and actively resist on-going white epistemological notions of us and the logic of patriarchal white sovereignty.

Cherbourg time : young black and deadly art 2003-2007

Art is most often at the margins of community life, seen as a distraction or entertainment only; an individual’s whim. It is generally seen as without a useful role to play in that community. This is a perception of grown-ups; children seem readily to accept an engagement with art making. Our research has shown that when an individual is drawn into a crafted art project where they have an actual involvement with the direction and production of the art work, then they become deeply engaged on multiple levels. This is true of all age groups. Artists skilled in community collaboration are able to produce art of value that transcends the usual judgements of worth. It gives people a licence to unfetter their imagination and then cooperatively be drawn back to a reachable visual solution. If you engage with children in a community, you engage the extended family at some point. The primary methodology was to produce a series of educationally valid projects at the Cherbourg State School that had a resonance into that community, then revisit and refine them where necessary and develop a new series that extended all of the positive aspects of them. This was done over a period of five years. The art made during this time is excellent. The children know it, as do their families, staff at the school, members of the local community and the others who have viewed it in exhibitions in far places like Brisbane and Melbourne. This art and the way it has been made has been acknowledged as useful by the children, teachers and the community, in educational and social terms. The school is a better place to be. This has been acknowledged by the children, teachers and the community The art making of the last five years has become an integral part of the way the school now operates and the influence of that has begun to seep into other parts of the community. Art needs to be taken from the margins and put to work at the centre.

Investigating international accounting standard setting : the black box of IFRS 6

This paper examines the role of powerful entities and coalitions in shaping international accounting standards. Specifically, the focus is on the process by which the International Accounting Standards Board (IASB) developed IFRS 6, Exploration for and Evaluation of Mineral Resources. In its Issues Paper, the IASB recommended that the successful efforts method be mandated for pre-production costs, eliminating the choice previously available between full cost and successful efforts methods. In spite of the endorsement of this view by a majority of the constituents who responded to the Issues Paper, the final outcome changed nothing, with choice being retained. A compelling explanation of this disparity between the visible inputs and outputs of the standard setting process is the existence of a “black box”, in which powerful extractive industries entities and coalitions covertly influenced the IASB to secure their own ends and ensure that the status quo was maintained

Hierarchical models for 2D presence/absence data having ambiguous zeroes: With a biogeographical case study on dingo behaviour

This dissertation is primarily an applied statistical modelling investigation, motivated by a case study comprising real data and real questions. Theoretical questions on modelling and computation of normalization constants arose from pursuit of these data analytic questions. The essence of the thesis can be described as follows. Consider binary data observed on a two-dimensional lattice. A common problem with such data is the ambiguity of zeroes recorded. These may represent zero response given some threshold (presence) or that the threshold has not been triggered (absence). Suppose that the researcher wishes to estimate the effects of covariates on the binary responses, whilst taking into account underlying spatial variation, which is itself of some interest. This situation arises in many contexts and the dingo, cypress and toad case studies described in the motivation chapter are examples of this. Two main approaches to modelling and inference are investigated in this thesis. The first is frequentist and based on generalized linear models, with spatial variation modelled by using a block structure or by smoothing the residuals spatially. The EM algorithm can be used to obtain point estimates, coupled with bootstrapping or asymptotic MLE estimates for standard errors. The second approach is Bayesian and based on a three- or four-tier hierarchical model, comprising a logistic regression with covariates for the data layer, a binary Markov Random field (MRF) for the underlying spatial process, and suitable priors for parameters in these main models. The three-parameter autologistic model is a particular MRF of interest. Markov chain Monte Carlo (MCMC) methods comprising hybrid Metropolis/Gibbs samplers is suitable for computation in this situation. Model performance can be gauged by MCMC diagnostics. Model choice can be assessed by incorporating another tier in the modelling hierarchy. This requires evaluation of a normalization constant, a notoriously difficult problem. Difficulty with estimating the normalization constant for the MRF can be overcome by using a path integral approach, although this is a highly computationally intensive method. Different methods of estimating ratios of normalization constants (N Cs) are investigated, including importance sampling Monte Carlo (ISMC), dependent Monte Carlo based on MCMC simulations (MCMC), and reverse logistic regression (RLR). I develop an idea present though not fully developed in the literature, and propose the Integrated mean canonical statistic (IMCS) method for estimating log NC ratios for binary MRFs. The IMCS method falls within the framework of the newly identified path sampling methods of Gelman & Meng (1998) and outperforms ISMC, MCMC and RLR. It also does not rely on simplifying assumptions, such as ignoring spatio-temporal dependence in the process. A thorough investigation is made of the application of IMCS to the three-parameter Autologistic model. This work introduces background computations required for the full implementation of the four-tier model in Chapter 7. Two different extensions of the three-tier model to a four-tier version are investigated. The first extension incorporates temporal dependence in the underlying spatio-temporal process. The second extensions allows the successes and failures in the data layer to depend on time. The MCMC computational method is extended to incorporate the extra layer. A major contribution of the thesis is the development of a fully Bayesian approach to inference for these hierarchical models for the first time. Note: The author of this thesis has agreed to make it open access but invites people downloading the thesis to send her an email via the 'Contact Author' function.

Modulation of dermal microvascular endithelial cell responses to growth factors and haemostatic factors in the presence of vitronectin

In order to effect permanent closure in burns patients suffering from full thickness wounds, replacing their skin via split thickness autografting, is essential. Dermal substitutes in conjunction with widely meshed split thickness autografts (+/- cultured keratinocytes) reduce scarring at the donor and recipient sites of burns patients by reducing demand for autologous skin (both surface area and thickness), without compromising dermal delivery at the wound face. Tissue engineered products such as Integra consist of a dermal template which is rapidly remodelled to form a neodermis, at which time the temporary silicone outer layer is removed and replaced with autologous split thickness skin. Whilst provision of a thick tissue engineered dermis at full thickness burn sites reduces scarring, it is hampered by delays in vascularisation which results in clinical failure. The ultimate success of any skin graft product is dependent upon a number of basic factors including adherence, haemostasis and in the case of viable tissue grafts, success is ultimately dependent upon restoration of a normal blood supply, and hence this study. Ultimately, the goal of this research is to improve the therapeutic properties of tissue replacements, through impregnation with growth factors aimed at stimulating migration and proliferation of microvascular endothelial cells into the donor tissue post grafting. For the purpose of my masters, the aim was to evaluate the responsiveness of a dermal microvascular endothelial cell line to growth factors and haemostatic factors, in the presence of the glycoprotein vitronectin. Vitronectin formed the backbone for my hypothesis and research due to its association with both epithelial and, more specifically, endothelial migration and proliferation. Early work using a platform technology referred to as VitroGro (Tissue Therapies Ltd), which is comprised of vitronectin bound BP5/IGF-1, aided keratinocyte proliferation. I hypothesised that this result would translate to another epithelium - endothelium. VitroGro had no effect on endothelial proliferation or migration. Vitronectin increases the presence of Fibroblast Growth Factor (FGF) and Vascular Endothelial Growth Factor (VEGF) receptors, enhancing cell responsiveness to their respective ligands. So, although Human Microvascular Endothelial Cell line 1 (HMEC-1) VEGF receptor expression is generally low, it was hypothesised that exposure to vitronectin would up-regulate this receptor. HMEC-1 migration, but not proliferation, was enhanced by vitronectin bound VEGF, as well as vitronectin bound Epidermal Growth Factor (EGF), both of which could be used to stimulate microvascular endothelial cell migration for the purpose of transplantation. In addition to vitronectin's synergy with various growth factors, it has also been shown to play a role in haemostasis. Vitronectin binds thrombin-antithrombin III (TAT) to form a trimeric complex that takes on many of the attributes of vitronectin, such as heparin affinity, which results in its adherence to endothelium via heparan sulfate proteoglycans (HSP), followed by unaltered transcytosis through the endothelium, and ultimately its removal from the circulation. This has been documented as a mechanism designed to remove thrombin from the circulation. Equally, it could be argued that it is a mechanism for delivering vitronectin to the matrix. My results show that matrix-bound vitronectin dramatically alters the effect that conformationally altered antithrombin three (cATIII) has on proliferation of microvascular endothelial cells. cATIII stimulates HMEC-1 proliferation in the presence of matrix-bound vitronectin, as opposed to inhibiting proliferation in its absence. Binding vitronectin to tissues and organs prior to transplant, in the presence of cATIII, will have a profound effect on microvascular infiltration of the graft, by preventing occlusion of existing vessels whilst stimulating migration and proliferation of endothelium within the tissue.

Identifying the presence of psychopathy in the community

Aim: Researchers have suggested that approximately 1% of individuals with psychopathic tendencies can successfully function within the community, although there has been a lack of research to support this claim. The current study aimed to identify individuals with psychopathic tendencies within a community sample and furthermore the socio-demographic correlates of this community integrated psychopath (e.g. relationship stability, substance use, and employment status). Procedure: 300 participants completed the Self-Reported Psychopathy scale – version 3 which contains four core psychopathy subfactors: (a) Interpersonal Manipulation, (b) Callous Affect, (c) Erratic Lifestyle and (d) Criminal Tendencies as well as the Paulhus Deception Scales to explore the effect of impression management and self-deception on the identification of psychopathy. Findings: Results indicated that at least 1% of the current community displayed characteristics consistent with psychopathic tendencies. A series of bivariate and multivariate statistical analyses were conducted which indicated that gender, age and alcohol misuse were predictive of psychopathy scores for this sample. More specifically, younger males who tend to misuse alcohol were found to be most likely to have psychopathic tendencies. Interestingly, impression management and self-deception was not associated with such tendencies. Discussion: The results provide some support for the assertion that individuals with psychopathic tendencies can be identified within the community (regardless of impression management techniques) and that such tendencies are associated with specific socio-demographic characteristics.

Operation and control of a DVR in the presence of interharmonics

The paper discusses the operating principles and control characteristics of a dynamic voltage restorer (DVR). It is assumed that the source voltages contain interharmonic components in addition to fundamental components. The main aim of the DVR is to produce a set of clean balanced sinusoidal voltages across the load terminals irrespective of unbalance, distortion and voltage sag/swell in the supply voltage. An algorithm has been discussed for extracting fundamental phasor sequence components from the samples of three-phase voltages or current waveforms having integer harmonics and interharmonics. The DVR operation based on extracted components is demonstrated. The switching signal is generated using a deadbeat controller. It has been shown that the DVR is able to compensate these interharmonic components such that the load voltages are perfectly regulated. The DVR operation under deep voltage sag is also discussed. The proposed DVR operation is verified through the computer simulation studies using the MATLAB software package.

Hearing impairment affects older people’s ability to drive in the presence of distracters

OBJECTIVES: To investigate the effects of hearing impairment and distractibility on older people's driving ability, assessed under real-world conditions. DESIGN: Experimental cross-sectional study. SETTING: University laboratory setting and an on-road driving test. PARTICIPANTS: One hundred seven community-living adults aged 62 to 88. Fifty-five percent had normal hearing, 26% had a mild hearing impairment, and 19% had a moderate or greater impairment. ---------- MEASUREMENTS: Hearing was assessed using objective impairment measures (pure-tone audiometry, speech perception testing) and a self-report measure (Hearing Handicap Inventory for the Elderly). Driving was assessed on a closed road circuit under three conditions: no distracters, auditory distracters, and visual distracters. RESULTS: There was a significant interaction between hearing impairment and distracters, such that people with moderate to severe hearing impairment had significantly poorer driving performance in the presence of distracters than those with normal or mild hearing impairment. CONCLUSION: Older adults with poor hearing have greater difficulty with driving in the presence of distracters than older adults with good hearing.

Modest visual impairments and headlamp glare reduce pedestrian visability at night

Background: This study investigated the effects of experimentally induced visual impairment, headlamp glare and clothing on pedestrian visibility. Methods: 28 young adults (M=27.6±4.7 yrs) drove around a closed road circuit at night while pedestrians walked in place at the roadside. Pedestrians wore either black clothing, black clothing with a rectangular vest consisting of 1325 cm2 of retroreflective tape, or the same amount of tape positioned on the extremities in a configuration that conveyed biological motion (“biomotion”). Visual impairment was induced by goggles containing either blurring lenses, simulated cataracts, or clear lenses; visual acuity for the cataract and blurred lens conditions was matched. Drivers pressed a response pad when they first recognized that a pedestrian was present. Sixteen participants drove around the circuit in the presence of headlamp glare while twelve drove without glare. Results: Visual impairment, headlamp glare and pedestrian clothing all significantly affected drivers’ ability to recognize pedestrians (p<0.05). The simulated cataracts were more disruptive than blur, even though acuity was matched across the two manipulations. Pedestrians were recognized more often and at longer distances when they wore “biomotion” clothing than either the vest or black clothing, even in the presence of visual impairment and glare. Conclusions: Drivers’ ability to see and respond to pedestrians at night is degraded by modest visual impairments even when vision meets driver licensing requirements; glare further exacerbates these effects. Clothing that includes retroreflective tape in a biological motion configuration is relatively robust to visual impairment and glare.

Left vs right in black and white : a review

LIKE much of the work that David Williamson is known for, Let the Sunshine concentrates on tensions between characters who operate mainly as mouthpieces for opposing ideologies. Left-wing documentary-maker Toby and his wife Ros have moved to Noosa to escape the rat race in Sydney and some bad press surrounding one of Toby's projects. Trying to make social connections in town, Ros has reconnected with high school classmate Natasha, now the cosmetically-enhanced wife of wealthy right-wing property developer Ron. The posturing and conflict between Toby and Ron come to a head when the women invite their grown children -- struggling songwriter Rick and stressed corporate lawyer Emma -- to dinner to celebrate Toby's birthday, and the results of this encounter drive the rest of the plot. The scenario of Let the Sunshine is contrived, the characters are stereotyped, and their conflicts are little more than an old clash of ideologies cast loosely across the mainstream news media's characterisation of the sides in debates about development, climate change and the economic crisis.