Tissue thickness calculation in ocular optical coherence tomography

Thickness measurements derived from optical coherence tomography (OCT) images of the eye are a fundamental clinical and research metric, since they provide valuable information regarding the eye’s anatomical and physiological characteristics, and can assist in the diagnosis and monitoring of numerous ocular conditions. Despite the importance of these measurements, limited attention has been given to the methods used to estimate thickness in OCT images of the eye. Most current studies employing OCT use an axial thickness metric, but there is evidence that axial thickness measures may be biased by tilt and curvature of the image. In this paper, standard axial thickness calculations are compared with a variety of alternative metrics for estimating tissue thickness. These methods were tested on a data set of wide-field chorio-retinal OCT scans (field of view (FOV) 60° x 25°) to examine their performance across a wide region of interest and to demonstrate the potential effect of curvature of the posterior segment of the eye on the thickness estimates. Similarly, the effect of image tilt was systematically examined with the same range of proposed metrics. The results demonstrate that image tilt and curvature of the posterior segment can affect axial tissue thickness calculations, while alternative metrics, which are not biased by these effects, should be considered. This study demonstrates the need to consider alternative methods to calculate tissue thickness in order to avoid measurement error due to image tilt and curvature.

Longitudinal changes in choroidal thickness and eye growth in childhood

PURPOSE To examine longitudinal changes in choroidal thickness and axial length in a population of children with a range of refractive errors. METHODS One hundred and one children (41 myopes and 60 nonmyopes) aged 10 to 15 years participated in this prospective, observational longitudinal study. For each child, 6-month measures of choroidal thickness (using enhanced depth imaging optical coherence tomography) and axial ocular biometry were collected four times over an 18-month period. Linear mixed-models were used to examine the longitudinal changes in choroidal thickness and the relationship between changes in choroidal thickness and axial eye growth over the study period. RESULTS A significant group mean increase in subfoveal choroidal thickness was observed over 18 months (mean increase 13 6 22 lm, P < 0.001). Myopic children exhibited significantly thinner choroids compared with nonmyopic children (P < 0.001), although there was no significant time by refractive group interaction (P ¼ 0.46), indicating similar changes in choroidal thickness over time in myopes and nonmyopes. However, a significant association between the change in choroidal thickness and the change in axial length over time was found (P < 0.001, β = −0.14). Children showing faster axial eye growth exhibited significantly less choroidal thickening over time compared with children showing slower axial eye growth. CONCLUSIONS A significant increase in choroidal thickness occurs over an 18-month period in normal 10- to 15-year-old children. Children undergoing faster axial eye growth exhibited less thickening and, in some cases, a thinning of the choroid. These findings support a potential role for the choroid in the mechanisms regulating eye growth in childhood.

Thickness metrics in posterior segment optical coherence tomography

To develop and compare a set of metrics for calculating tissue thickness in wide-field OCT data.

Longitudinal changes in choroidal thickness in childhood

• Evidence from cross-sectional studies1,2 suggests that choroidal thickness (ChT) varies with age and refractive error in childhood. However, to date there have been no longitudinal studies examining changes in pediatric ChT. • In this prospective study, the longitudinal changes in ChT and its relationship with eye growth were examined in a population of normal children with a range of refractive errors.

Vibrations of annular plates with linear thickness profiles

Abstract is not vailable.

'Create a Better Online You': Designing online learning resources to develop undergraduate social media skills

This article charts the development of the 'Create a Better Online You' (CBOY) project. The focus of CBOY was the social media skills of undergraduate students at QUT. While many students will have encountered 'cybersafety' training in primary or secondary school, however, a comprehensive environmental scan revealed little in the way of social media resources targeted at undergraduate students. In particular, there was little to no focus on the ways in which social media could be used strategically to develop a positive online reputation and enhance chances of employability post tertiary education. The resources created as part of CBOY were the result of a comprehensive literature review, environmental scan, interviews with key internal and external stakeholders, and in discussion with undergraduate students at Queensland University of Technology (QUT). Following the comprehensive environmental scan, it appears that CBOY represents one of the first free, openly accessible, interactive resources targeting the social media skills of undergraduates.

Formalising the vernacular: Social media skills in higher education

This paper discusses the issue of social media skills using a literacy framework. Firstly, it argues that social media skills are a form of vernacular, or ‘everyday’, literacy and articulates the issues associated with trying to formalise these skills within the curriculum. Secondly, it calls for greater explicit attention to social media skills within higher education, by arguing that social media literacies are a part of new literacies. It evaluates QUT’s “Create a Better Online You” suite of social media resources in light of this framework, and discusses the role of libraries in addressing social media skills.

Participatory media and 'co-creative' storytelling

Distinguishing critical participatory media from other participatory media forms (for example user-generated content and social media) may be increasingly difficult to do, but nonetheless remains an important task if media studies is to remain relevant to the continuing development of inclusive social political and media cultures. This was one of a number of the premises for a national Australian Research Council-funded study that set out to improve the visibility of critical participatory media, and understand its use for facilitating media participation on a population wide basis (Spurgeon et. al. 2015). The term ‘co-creative’ media was adopted to make this distinction and to describe an informal system of critical participatory media practice that is situated between major public, Indigenous and community arts, culture and media sectors. Although the co-creative media system is found to be a site of innovation and engine for social change its value is still not fully understood. For this reason, this system continues to provide media and cultural studies scholars with valuable sites for researching the sociocultural transformations afforded by new media and communication technologies, as well as their limitations.

Chapter 1: Precarious creativity: Global media, local labor

In most parts of the world, screen media workers—actors, directors, gaffers, and makeup artists—consider Hollywood to be glamorous and aspirational. If given the opportunity to work on a major studio lot, many would make the move, believing the standards of professionalism are high and the history of accomplishment is renowned. Moreover, as a global leader, Hollywood offers the chance to rub shoulders with talented counterparts and network with an elite labor force that earns top-tier pay and benefits. Yet despite this reputation, veterans say the view from inside isn’t so rosy, that working conditions have been deteriorating since the 1990s if not earlier. This grim outlook is supported by industry statistics that show the number of good jobs has been shrinking as studios outsource production to Atlanta, London, and Budapest, among others...

Free vibration of rectangular plates of arbitrary thickness

Free vibration of thick rectangular plates is investigated by using the “method of initial functions” proposed by Vlasov. The governing equations are derived from the three-dimensional elastodynamic equations. They are obtained in the form of series and theories of any desired order can be constructed by deleting higher terms in the infinite order differential equations. The numerical results are compared with those of classical, Mindlin, and Lee and Reismann solutions.

Scar outcome of children with partial thickness burns: A 3 and 6 month follow up

INTRODUCTION There is a paucity of research investigating the scar outcome of children with partial thickness burns. The aim of this study was to assess the scar outcome of children with partial thickness burns who received a silver dressing acutely. METHOD Children aged 0-15 years with an acute partial thickness burn, ≤10% TBSA were included. Children were originally recruited for an RCT investigating three dressings for partial thickness burns. Children were assessed at 3 and 6 months after re-epithelialization. 3D photographs were taken of the burn site, POSAS was completed and skin thickness was measured using ultrasound imaging. RESULTS Forty-three children returned for 3 and 6 month follow-ups or returned a photo. Days to re-epithelialization was a significant predictor of skin/scar quality at 3 and 6 months (p<0.01). Patient-rated color and observer-rated vascularity and pigmentation POSAS scores were comparable at 3 months (color vs. vascularity 0.88, p<0.001; color vs. pigmentation 0.64, p<0.001), but patients scored higher than the observer at 6 months (color vs. vascularity 0.57, p<0.05; color vs. pigmentation 0.15, p=0.60). Burn depth was significantly correlated with skin thickness (r=0.51, p<0.01). Hypopigmentation of the burn site was present in 25.8% of children who re-epithelialized in ≤2 weeks. CONCLUSION This study has provided information on outcomes for children with partial thickness burns and highlighted a need for further education of this population.

Randomised controlled trial of three burns dressings for partial thickness burns in children

BACKGROUND This study compared the effects of three silver dressing combinations on small to medium size acute partial thickness burns in children, focusing on re-epithelialization time, pain and distress during dressing changes. METHOD Children (0-15 years) with clean, ≤ 10% total body surface area (TBSA) partial thickness burns who met the inclusion criteria were included in the study. Children received either (1) Acticoat™; (2) Acticoat™ with Mepitel™; or (3) Mepilex Ag™ dressings. Measures of burn re-epithelialization, pain, and distress were recorded at dressing changes every 3-5 days until full re-epithelialization occurred. RESULTS One hundred and three children were recruited with 96 children included for analysis. No infections were detected for the course of the study. When adjusted for burn depth, Acticoat™ significantly increased the expected days to full re-epithelialization by 40% (IRR = 1.40; 95% CI: 1.14-1.73, p < 0.01) and Acticoat™ with Mepitel™ significantly increased the expected days to full re-epithelialization by 33% (IRR = 1.33; 95% CI: 1.08-1.63, p ≤ 0.01) when compared to Mepilex Ag™. Expected FLACC scores in the Mepilex Ag™ group were 32% lower at dressing removal (p = 0.01) and 37% lower at new dressing application (p = 0.04); and scores in the Acticoat™ with Mepitel™ group were 23% lower at dressing removal (p = 0.04) and 40% lower at new dressing application (p < 0.01), in comparison to the Acticoat™ group. Expected Visual Analog Scale-Pain (VAS-P) scores were 25% lower in the Mepilex Ag™ group at dressing removal (p = 0.04) and 34% lower in the Acticoat™ with Mepitel™ group (p = 0.02) at new dressing application in comparison to the Acticoat™ group. There was no significant difference between the Mepilex Ag™ and the Acticoat™ with Mepitel™ groups at all timepoints and with any pain measure. CONCLUSION Mepilex Ag™ is an effective silver dressing, in terms of accelerated wound re-epithelialization time (compared to Acticoat™ and Acticoat™ with Mepitel™) and decreased pain during dressing changes (compared to Acticoat™), for clean, < 10% TBSA partial thickness burns in children.

Stillness: A meditation in new media art

While technology is often seen as a noisy, impatient and pervasive aspect of our lives, this practice-led research project investigated the counter proposition–that we might be able to evoke sensations of stillness through technology-mediated artworks. Investigations into stillness were informed by Buddhism, phenomenology, and experiences of meditation and the practice of archery. By combining visual art, performance, installation, video and interaction design, a series of experimental, interdisciplinary artworks were produced and exhibited to evoke a sense of stillness and to impel audiences to consider the form and nature of stillness in relation to time, space and motion.

Private power and new media: The case of the corporate suppression of WikiLeaks and its implications for the exercise of fundamental rights on the internet

Globalization, along with its digital and information communication technology counterparts, including the Internet and cyberspace, may signify a whole new era for human rights, characterized by new tensions, challenges, and risks for human rights, as well as new opportunities. Human Rights and Risks in the Digital Era: Globalization and the Effects of Information Technologies explores the emergence and evolution of ‘digital’ rights that challenge and transform more traditional legal, political, and historical understandings of human rights. Academic and legal scholars will explore individual, national, and international democratic dilemmas--sparked by economic and environmental crises, media culture, data collection, privatization, surveillance, and security--that alter the way individuals and societies think about, regulate, and protect rights when faced with new challenges and threats. The book not only uncovers emerging changes in discussions of human rights, it proposes legal remedies and public policies to mitigate the challenges posed by new technologies and globalization.

Effect of concentrated force on a Crack in dissimilar media

Efect of concentrated force or edge dislocation with Burger's vector on a line crack in di,aimilar media has been studied in this paper. Crack surfaces may be subjected to surface loads or opuwd by rigid inclusions. Complex variable methods have been employed to study the distribution of stresses and displacements every where and in particnlar at the tips of the crack.