The role of fixation disengagement and oculomotor preparation in gap saccade task is gap-duration dependent

The influence of internal brain state on behavioral performance is well illustrated by the gap-saccade task, in which saccades might be initiated with short latency (express saccade) or with long latency (regular saccade) even though the external visual condition is identical. Accumulated evidence has demonstrated that the internal brain state is different before the initiation of an express saccade than of a regular saccade. However, the reported origin of the fluctuation of internal brain state is disputed among previous studies, e.g., the fixation disengagement theory versus the oculomotor preparation theory. In the present study, we examined these two theories by analyzing the rate and direction of fixational saccades, i.e., small amplitude saccades during fixation period, because they could be modulated by internal brain state. Since fixation disengagement is not spatially tuned, it might affect the rate but not direction of fixational saccade. In contrast, oculomotor preparation can contain the spatial information for upcoming saccade, thus, it might have a distinct effect on fixational saccade direction. We found that the different spatiotemporal characteristics of fixational saccades among tasks with different gap durations reveals different driven force to change the internal brain state. Under short gap duration (100 ms), fixation disengagement plays a primary role in switching internal brain state. Conversely, under medium (200 ms) and long (400 ms) gap durations, oculomotor preparation plays a primary role. These results suggest that both fixation disengagement and oculomotor preparation can change the internal brain state, but their relative contributions are gap-duration dependent.

Critical Analysis of Corneal Cross-Linking (Part-II): Resolving the Controversial Issues (Theory Versus Measurements)

To resolve the controversial issues of UV-light-initiatedcornealcollagen cross-linking (CXL) by theoretical formulas and measured clinical outcomes. The controversial issues are addressed and resolved by analytical formulas including: the validation of Bunsen Roscoe law (BRL), the cutoff light intensity, the minimum corneal thickness, the demarcation line depth, the role of oxygen riboflavin (RF) concentration. The overall CXL efficacy is governed by UV-A light intensity, dose, exposure time, mode of exposure (pulsed or CW), riboflavin concentration, diffusion and drops pre-operation and interoperation administration, concentration of oxygen in the stromal tissue (pre-op and inter-op), and environmental conditions. The length of the riboflavin presoaking time and viscosity of the riboflavin film also affect the crosslink depth. Analytic formulas are derived for the scaling laws for type-I and type-II efficacy, given by the square-root of light intensity, and light dose, respectively. The controversial issues of CXL may be partially resolved via analytic formulas, and compared with measurements. The scaling laws of type-I and type-II efficacy are different and given by analytic formulas. Our formulas also predict the maximum light intensity and the minimum corneal thickness, which are consistent with measurements.

Children’s Right to Health: Theory versus Practice

Introduction A research was conducted from 2014 to 2018 to understand the reasons behind the gap between the theoretical affirmation of children’s right to health and its practical realization. Hospitals and healthcare services were chosen as possible settings to understand these reasons and identify the gap. Methods Questionnaires (open-ended questions) were completed throughout the year 2017 with experts working at International level in the field of children’s rights. A survey was set up using a structured multiple-choice questionnaire in Italian, English, and French. The survey was addressed to hospital staff (professionals; managers and administrative staff). All the results from the experts’ questionnaires and from the survey were elaborated using Excel. Result Experts concluded that professionals still have to understand the full value of implementing children’s rights in hospitals and that the United Nations should empower their own action in order to push states towards the respect and full realization of the Convention on the Rights of the Child. The survey results seem to confirm that in healthcare settings professionals’ have difficulties in understanding how to relate to children in order to facilitate the full realization of their right to health. Conclusion The investigation confirmed the existence of a ‘perceptive astigmatism’ as guiding factor for professionals’ behaviour towards children.