The Development of Crowding and Interocular Interactions in a Resolution Acuity Task

Purpose.: To investigate the impact of interocular similarities of a surround stimulus on foveal resolution acuity in the normally developing visual system. Methods.: Liquid crystal shutter goggles synchronized with the monitor frame rate were used to present a Landolt C and surround bars to one or both eyes, in monocular, dichoptic, half-binocular, and binocular viewing conditions. Resolution acuity was measured under each condition in 56 normally sighted children (7 to 14 years of age) and 22 adults (21 to 38 years of age). The effect of the surround bars (crowding) was tested in a subgroup of nine children, and 10 adults. Results.: Across all age groups resolution acuity was significantly better in the binocular condition than in the other three viewing conditions (binocular summation), and was significantly better in the half-binocular (with target presented to the test eye and bars presented to both eyes) than in the dichoptic condition (target presented to test eye and bars presented to the nontested eye only). In children, but not in adults, resolution acuity was significantly better without than with bars. Conclusions.: The interocular similarities may explain the better visual resolution in the half-binocular condition than in the dichoptic condition for all age groups tested. The results suggest that interocular interactions underpinning resolution acuity under these viewing conditions are developed in early childhood. The foveal crowding effect was found to be apparent at the beginning of school age, and diminished with maturation

Enhancement of Resolution Acuity in a Half-Binocular Viewing Condition

Purpose.: To investigate the effect of interocular stimulus similarity on foveal resolution acuity. Methods.: Liquid crystal shutter goggles synchronized with the monitor refresh rate were used to present a Landolt C and surround bars to one or both eyes, in four viewing conditions (monocular, dichoptic, half-binocular, and binocular). Resolution acuity was measured in each condition in 22 normally sighted adults. Results.: Resolution acuity was significantly better in the binocular condition than in the other three viewing conditions (binocular summation) and was significantly better in the half-binocular condition (with target presented to the test eye and bars presented to both eyes) than in the dichoptic condition (target presented to the test eye and bars presented to the nontested eye only). Conclusions.: Monocular resolution acuity depends in part on interocular similarities of the stimulus surrounding the central target. This finding may have implications in the design of stimuli for vision-training therapies

Using a chronic hepatitis B Registry to support population-level liver cancer prevention in Sydney, Australia

Monica C Robotin,1–3 Ximena Masgoret,1 Mamta Porwal,4 David Goldsbury,5 Chee Khoo,6,7 Jacob George,2,3 1School of Medicine, The University of Notre Dame Australia, Darlinghurst, 2Faculty of Medicine, University of Sydney, Camperdown, 3Storr Liver Center, Westmead Institute for Medical Research, Westmead Hospital, Westmead, 4Australian School of Graduate Management, University of New South Wales, Kensington, 5Cancer Council NSW, Woolloomooloo, 6Royal Australasian College of General Practitioners, Sydney, 7University of Western Sydney, Macarthur, NSW, Australia Background: Approximately 1% of Australians have chronic hepatitis B (CHB), which disproportionately affects people born in hepatitis B-endemic countries. Currently, approximately half of the people affected remain undiagnosed and antiviral treatment uptake is suboptimal (~5%). This increases the likelihood of developing end-stage disease complications, particularly hepatocellular cancer (HCC), and largely accounts for the significant increases in HCC incidence and mortality in Australia over the last decades. As our previous economic modeling suggested that CHB screening and treatment is cost-effective, we tested the feasibility of a primary care-based model of CHB diagnosis and management to prevent HCC.Materials and methods: From 2009 to 2016, the B Positive program trialed a CHB screening and management program in an area of high disease prevalence in Sydney, Australia. Trained local primary care providers (general practitioners) screened and managed their CHB patients using a purpose-built CHB Registry and a risk stratification algorithm, which allocated patients to ongoing primary care-based management or specialist referral.Results: The program enrolled and followed up >1,500 people (25% of the target population). Their median age was 48 years, with most participants being born in China (50%) or Vietnam (32%). The risk stratification algorithm allocated most Registry participants (n=847 or 79%) to primary care-based management, reducing unnecessary specialist referrals. The level of antiviral treatment uptake in Registry patients was 18%, which was the optimal level in this population group.Conclusion: This pilot program demonstrated that primary care-based hepatitis B diagnosis and management is acceptable to patients and their care providers and significantly increases compliance with treatment guidelines. This would suggest that scaling up access to hepatitis B treatment is achievable and can provide a means to operationalize a population-level approach to CHB management and liver cancer prevention. Keywords: hepatitis B Registry, primary care, cancer prevention, antiviral treatment, risk stratificatio

Researching L2 motivation : past, present and future

This concluding chapter examines the ‘how’ of language learning motivation research–that is, the methodological approaches, research designs, and tools of inquiry used to investigate motivation for language learning. The purpose of the chapter is to survey the diverse range of approaches to researching L2 (second language) motivation, with reference to particular types of study and particular research traditions. The chapter does not provide a practical “how to” guide for specific methods of inquiry, but aims instead to offer a critical analysis of strengths, limitations and challenges associated with different approaches to investigating language learning motivation. As reflected in its title, the chapter takes a broadly historical perspective and reviews how research designs have evolved and diversified over the decades in line with theoretical developments, broader research trends, and advances in technology. It discusses recent methodological innovations in the field, identifies current research challenges and issues, and outlines considerations for researching language learning motivation in the future