Separate first- and second-order processing is supported by spatial summation estimates at the fovea and eccentrically

AbstractWe estimated spatial summation areas for the detection of luminance-modulated (LM) and contrast-modulated (CM) blobs at the fovea, 2.5, 5 and 10deg eccentrically. Gaussian profiles were added or multiplied to binary white noise to create LM and CM blob stimuli and these were used to psychophysically estimate detection thresholds and spatial summation areas. The results reveal significantly larger summation areas for detecting CM than LM blobs across eccentricity. These differences are comparable to receptive field size estimates made in V1 and V2. They support the notion that separate spatial processing occurs for the detection of LM and CM stimuli

Driving and glaucoma in the UK: a national survey of clinicians’ advice and guidance to patients

Introduction: Driving standards policy is set by the Department for Transport and executed by the Driving and Vehicle Licensing Agency (DVLA). Professional bodies recognise the challenges that clinicians face when advising patients with glaucoma about driving. This study explored clinicians’ knowledge and confidence around driving standards and their approach to advising and guiding patients. Methods: Cross-sectional online survey of all United Kingdom and Eire Glaucoma Society (UKEGS) members. The survey remained open for five weeks (22/02/21–27/03/21). Anonymised data were exported to Microsoft Excel for analysis. Results: Out of 91 respondents (minimum response rate 20.2%), 53 (58.2%) were glaucoma consultants, 2 (2.2%) general consultant ophthalmologists, 4 (4.4%) ophthalmology fellows, 5 (5.5%) ophthalmology trainees, 19 (20.9%) optometrists, and 8(8.8%) ‘other’ categories (one SAS doctor, six specialist doctors, one nurse specialist). 58.2% reported that the visual standards for driving were ‘very familiar’; 40.5% were ‘moderately familiar’; one(1.2%) was only ‘somewhat familiar’; none were completely unfamiliar. A total of 38 (41.8%) respondents were highly confident in giving advice on fitness to drive; 51 (56.0%) were moderately confident; 2 (2.2%) had only limited confidence. Over 25% review patients not meeting driving standards in every glaucoma clinic, over 50% identifying abnormal visual fields as the main reason. Conclusion: Our study found that most clinicians are familiar with DVLA driving standards. However, busy clinical environments limit detailed discussion about this, leading to only one in four clinicians being very confident to broach the subject with patients in clinic. A range of patient education modalities were suggested, which may help simplify advice provision for glaucoma patients.</p

Static hypochlorite induced accelerated ageing of RO membranes: The effect of PH on performance

Understanding the phenomena responsible for membranes ageing is of crucial importance for optimal operation. The declining functionality associated with ageing includes changes in physical parameters, such as, thickness, roughness and density of defects, but also in chemical structure, including, H-bonds density, amide substitution degree and aromatic ring chlorination. All these factors contribute synergistically to the major performance indicators: membrane permeability and rejection. This study shows a significant dependence of clean water and saline solution permeability with the pH of the chlorinating solution, with little effect on the salt rejection. It also highlights the ability of microscopy and microanalysys methods to measure the changes induced by ageing

Quality of life in persons living with advanced glaucoma in South India

Abstract Purpose Glaucoma can significantly affect visual functions, independence, mobility, and quality of life (QoL), particularly in the advanced stage. Physical health, emotional state, and socioeconomic status can influence the QoL. This study aimed to understand the QoL of glaucoma patients attending tertiary eye hospital in south India. Methods Glaucoma patients from rural/semi-urban region were interviewed using a semi-structured interview guide in their vernacular language to capture the challenges and limitations in their daily lives due to glaucoma. Audio-recorded interviews were transcribed verbatim, and thematic analysis was performed to understand their QoL. Results Twenty patients [75% (n = 15) males] were interviewed, and six themes were identified. Many (75%) sought medical advice after vision disturbances leading to a glaucoma diagnosis. Half (50%) were identified in routine exams, and few self-referred due to positive family history. Adapting was challenging, affecting daily activities, work, mobility, dark adaptation, and medication discomfort. Many (40%) accepted their condition, while a few (25%) struggled with fear, depression, and frustration upon diagnosis, emotional distress, and social isolation. Financial burdens were significant for many due to losing jobs, and few relied on pensions. Adaptive strategies include engaging in physical activity, spending time with family members, and engaging in social activities. Conclusion Patients presenting late with advanced glaucoma to rural/semi-urban eye hospital in India experience significantly affect their QoL. Healthcare providers can better support glaucoma patients by identifying patients with functional and psychological distress using structured questionnaires, creating awareness of the condition and advising them with constructive coping strategies/referrals for counselling

Effect of pH on the ageing of reverse osmosis membranes upon exposure to hypochlorite

The declining functionality associated with membranes ageing includes changes in physical parameters, such as, thickness, roughness and density of defects, but also in chemical structure. All these factors impact synergistically on the major performance indicators: permeability and salt rejection. In this study, three types of commercially available RO membranes were statically exposed to hypochlorite solutions and analysed by Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) in conjunction with performance tests. IR data support the chemical structure alteration for samples aged at pHs 7 and 4, where hypochlorous acid (HOCl) is the main oxidant. For two of the membranes, AFM results indicate increasing roughness at pH 4. Performance tests show a reduction of de-ionised (DI) water and brackish water permeability at pH 7 and pH 4, while at pH 10, where hypochlorite ion (CIO-) is abundant, permeability increases. Salt rejection results vary in a narrow interval of 5% and depend on the type of membrane. Based on these results the ppm.h concept appears to fail to express a simple ageing kinetic over the entire range of pH, owing to the competing mechanisms of ring chlorination and surface hydrolysis of amide groups. (C) 2012 Elsevier B.V. All rights reserved