Corneal structure and transparency

The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency.     

Decoding disclosure: Comparing conflict of interest policy among the United States,France, and Australia

“Sunshine” policy, aimed at making financial ties between health professionals and industry publicly transparent, has recently gone global. Given that transparency is not the sole means of managing conflict of interest, and is unlikely to be effective on its own, it is important to understand why disclosure has emerged as a predominant public policy solution, and what the effects of this focus on transparency might be. We used Carol Bacchi’s problem-questioning approach to policy analysis to compare the Sunshine policies in three different jurisdictions, the United States, France and Australia. We found that transparency had emerged as a solution to several different problems including misuse of tax dollars, patient safety and public trust. Despite these differences in the origins of disclosure policies, all were underpinned by the questionable assumption that informed consumers could address conflicts of interest. We conclude that, while transparency reports have provided an unprecedented opportunity to understand the reach of industry within healthcare, policymakers should build upon these insights and begin to develop policy solutions that address systemic commercial influence.     

Evaluating the transparency of pharmaceutical company disclosure of payments to patient organisations in the UK

Patient organisations contribute to many areas of pharmaceutical policy. In developing their organisational capacity, many turn to financial support from pharmaceutical companies, which may create conflicts of interests. However, the transparency of the industry’s self-regulatory approach to the disclosure of payments to patient organisations has evaded scrutiny. Using company reports disclosing payments to UK patient organisations in 2012–2016, we evaluate the transparency of reporting using indicators derived from industry’s European patient organisation Code. We found a large proportion of companies did not have any disclosure reports available despite many having made payments, confirmed by comparing with annual financial accounts of patient organisations registered as charities. Where disclosure reports were available, many payments were not adequately described, resulting in large portions of money being disclosed without clarity as to the payment type and purpose. We found companies were clearer regarding whether payments were financial or benefits-in-kind, but transparency was particularly inadequate as to whether it could be determined if payments were indirect or direct and restricted or unrestricted, and almost no companies mentioned the VAT status of payments. Our findings suggest that the industry’s self-regulatory approach to transparency has not been working efficiently. We suggest ways for standardising and increasing the precision of information by pharmaceutical companies and advocate for the introduction of a centralised, and easily accessible national-level payment database.     

The peculiar nature of simultaneous colour contrast in uniform surrounds

We present evidence from asymmetric colour matching experiments which strongly suggests that uniform surrounds evoke induction effects of a very peculiar nature, not representative of colour induction effects in variegated surrounds. Given the widespread use of uniform surrounds in studies of colour vision, this finding is of interest in relation to a number of current research issues, such as contrast coding of colour, functionally equivalent surrounds and colour constancy. A framework that systematises the seemingly complex colour appearance changes induced by uniform surrounds is presented and its implications are discussed.     

Segregation from direction differences in dynamic random-dot stimuli

Previous research has shown that a field of random dots in which each dot alternates between a slow and a fast speed, can give rise to the percept of two superimposed sheets of moving dots when the alternations are out of phase or asynchronous with each other [Vis. Res. 35 (1995) 1691]. Under those conditions, observers can discriminate changes in the slow speed independent of changes in the fast speed. The present study investigated whether such motion-based segregation could result when dots alternated between two different directions. Three observers viewed a variety of displays containing two directions of motion, one upward and one oblique, with the task of discriminating small trial-to-trial changes in the direction of the upward component. The oblique direction component also changed direction from trial-to-trial. The field of dots either alternated synchronously (all dots moved in the same direction and switched to the other direction simultaneously) or asynchronously. Results showed that when the dots alternated synchronously between the directions, observers' direction discrimination performance was generally poor. However, when dots switched directions asynchronously, direction discrimination was only slightly elevated in comparison to that produced by a field of dots all moving in a single direction. Additional experiments demonstrated that this performance was not due to judging the global direction of the random-dot display. Thus the visual system had to segregate the stimulus into its component directions before integrating to arrive at the motion signal to be discriminated. It is concluded that for displays comprising elements that alternate between different directions, local direction signals can be used by the human visual system to effectively segregate a display so long as both direction signals are present simultaneously.     

塑料镜片材料的发展动向

概述光学塑料的基本材料，讨论塑料镜片材料的主要品种及其应用，并着重分析影响塑料镜片材料性能的主要因素及其发展趋势。     

The role of National Immunization Technical Advisory Groups (NITAG) in strengthening health system governance: Lessons from three middle-income countries—Argentina,Jordan, and South Africa (2017–2018)

IntroductionToward the Global Vaccine Action Plan 2020 goal, almost 90% of countries have established a National Immunization Technical Advisory Group (NITAG). However, little is known about NITAG's contributions to governance.MethodsIn 2017–2018, a two-step, qualitative retrospective study was conducted. Jordan (JO), Argentina (AR), and South Africa (SA) were selected owing to government-financed NITAGs from middle-income countries (MICs), geographic diversity, and a vaccine introduction with NITAG support. Country case studies were developed, collecting data through desk review and face-to-face key informant interviews (KIIs) from Ministry of Health (MoH) and NITAG. Case studies were analyzed together, to assess governance applying the European Observatory on Health Systems and Policies framework focusing on transparency, accountability, participation, integrity, and policy capacity (TAPIC).ResultsDocument review and 53 KII (22 AR, 20 SA, 11 JO) showed NITAGs played a pivotal role as advisors promoting a culture of evidence-informed policies. NITAGs strengthened governance, although practices varied among countries. Meetings were conducted behind-closed-doors, participation restricted to members, only in one country agendas, and recommendations were public (AR). To increase participation, policy capacity, and transparency, countries considered adding experts in communications, advocacy, and economics. AR and SA contemplated including community members. NITAGs functioned autonomously from the government, with no established internal or external monitoring or supervision. NITAG meeting minutes allowed the review of integrity, adherence to terms of reference, standard operating procedures, and conflict of interest (CoI). For the most part, NITAGs abided by their mandates. Significant issues were related to the level of MoH support and oversight of CoI declaration and documentation.ConclusionsSystematically implementing governance approaches could improve processes, better tailor policies, and implementation. The long-term survival and resilience of NITAGs in these countries showed they play a significant role in strengthening governance. Lessons learned could be useful to those promoting country-driven evidence-informed decision-making.     

FDA透明度行动简介及其特点和作用分析

目的:为我国食品药品监督管理局(SFDA)政务公开工作的完善提供参考。方法:通过查阅美国食品与药品管理局(FDA)透明度行动文献,应用文献研究方法对FDA透明度行动进行了介绍,并对其特点及作用进行了系统的分析。结果:FDA通过透明工作组、绩效追踪等一系列的透明度行动,扩大了信息公开的广度和深度,提高了自身工作的透明度。结论:我国可借鉴FDA的经验,采取相应措施使SFDA的工作更加透明化。