We have developed the world's first novel type of artificial retina, OUReP (Okayama University Retinal Prosthesis), in which a photoelectric dye that converts light energy into electric potential is covalently bonded to the surface of a polyethylene thin film as an insulator. The receptor that absorbs light and the output device that generates displacement current to stimulate nearby neurons are integrated in a sheet of thin film. It has become possible to measure the surface potential of the artificial retina OUReP using a Kelvin probe that measures the surface potential of semiconductors. When light is turned on and off to the artificial retina OUReP, the surface potential changes rapidly. As the light intensity is increased, the potential change on the surface of the artificial retina becomes larger. As for safety, the artificial retina OUReP was not toxic in all tests for biological evaluation of medical devices. As for efficacy, the artificial retina OUReP was implanted under the retina by vitreous surgery in monkey eyes which had chemically-induced macular degeneration with photoreceptor cell loss. Over the next 6 months, retinal detachment did not occur during the course, and the artificial retina was in contact with the retinal tissue. The amplitude of the visual evoked potential attenuated by macular degeneration recovered 1 month after implantation of the artificial retina, and the recovery of amplitude was maintained until 6 months after the implantation. By using multielectrode array-mounted dish recording system, it has been proved that action potential spikes are induced when the artificial retina is placed on degenerative retinal tissue of retinal dystrophic rats or mice and exposed to light, which is used as an index of the effectiveness of the artificial retina. We have established manufacturing and quality control of the device in a clean room facility, proved the safety and efficacy, and are preparing for first-in-human investigator-initiated clinical trials.
School stress is one of the most important stressors in adolescents around the world. This study tested the impact of region, age, gender, family structure, and school achievement on adolescents’ stress perception. In a cross-sectional design, 12.172 adolescents from 21 countries participated in the study. Adolescents from Central European and North American countries had generally quite low levels of school stress. Adolescents from Southern Europe exhibited the highest stress levels, but also adolescents from Latin America, the Middle East and Asian countries reported quite high levels of school-related stress. Rank 1 in many countries was the pressure to get the best marks. Additionally, the fear that differences in opinion with the teacher may result in bad marks and that the leaning material is too difficult or too boring were also important stressors, whereas rivalries among pupils seemed not to be a major problem. Adolescents from single-parent families experienced higher school-related stress than adolescents from two-parent families. The findings were discussed with respect to overall globalization and future insecurities, leading to universal stressors of adolescents in different parts of the world.
Social withdrawal behaviour in infants is a key indicator of child distress and a risk factor for later pathologies. The present study provides results from a Moroccan study of the ADBB scale applied to two populations that were very different in terms of early separation experiences: babies living in a children’s home (n=46) and babies raised by their families (n=56). These 102 infants were assessed using the ADBB scale during routine paediatric check-ups between the ages of 2 and 18 months. Social withdrawal behaviour was significantly more marked among infants raised in a children’s home than among infants raised by their family, and more so among boys than among girls. This study comprising a control group confirmed the validity of Spitz’s description, which placed social withdrawal at the centre of anaclitic depression and of the causes of hospitalism, and attributed this withdrawal to the infants’ early and prolonged separation from their caregivers. The use of the scale stay therefore be recommended for systematic detection during routine paediatric check-ups or for the follow-up of children at risk, to enable appropriate early interventions to take place.
Hippocampus plays an important role in processing episodic memory. The different patterns of multi-unit activity (MUA) of CA1 neurons in hippocampus corresponds to the different high order functions of the brain such as memory, association, planning, action decision, etc. In this paper, a deep learning model, which is a composition of convolutional neural network (CNN) and support vector machine (SVM), is adopted to classify 4 kinds of episodic memories of a male rat: restraint stress (restraint), contact with a female rat (female), contact with a male rat (male), and contact with a novel object (object). In addition, the characteristic patterns of the different events occurred in CA1 neurons are specified by the feature explanation of CNN using Grad-CAM. As the result, this study suggests that it is available to recognize episodic memories by MUA signals and vice versa.
More and more people practice mindfulness to reduce stress and improve their wellbeing. In this regards, technology-based interventions such as smartphone apps provide an interesting potential. Our study explores effects on users' perceived wellbeing and stress on the example of the mindfulness-based app My Blossom. Forty-four new users answered four online questionnaires in one-week intervals, containing established multi-item wellbeing and stress scales for as well as single-item direct explicit questions about perceived changes in wellbeing and stress. In combination, these two forms of assessment provided insights to what degree users are conscious of a possible change and whether these perceptions are in parallel to the more indirect measures. Paired t tests show significant improvements in positive and negative affect, mood and stress in both scales and overall ratings after three weeks of mindfulness-training with My Blossom compared to the pre-intervention baseline. These findings suggest mindfulness-training in form of an app as an interesting alternative to mindfulness-trainings under instructions of a physically present trainer and the power to increase wellbeing and decrease stress. Future research should concentrate on the specific mechanisms and possible design factors of app-based mindfulness-trainings (e.g., variety of training offers, degree of guidance, reminder functions) as well as long term effects.
