Artificial electronic synapses are commonly used to simulate biological synapses to realize various learning functions, regarded as one of the key technologies in the next generation of neurological computation. This work used a simple spin coating technique to fabricate polyimide (PI):graphene quantum dots(GQDs) memristor structure. As a result, the devices exhibit remarkably stable exponentially decaying postsynaptic suppression current over time, as interpreted in the spike-timing-dependent plasticity phenomenon. Furthermore, with the increase of the applied electrical signal over time, the conductance of the electrical synapse gradually changes, and the electronic synapse also shows plasticity dependence on the amplitude and frequency of the pulse applied. In particular, the devices with the structure of Ag/PI:GQDs/ITO prepared in this study can produce a stable response to the stimulation of electrical signals between millivolt to volt, showing not only high sensitivity but also a wide range of "feelings", which makes the electronic synapses take a step forwards to emulate biological synapses. Meanwhile, the electronic conduction mechanisms of the device are also studied and expounded in detail. The findings in this work lay a foundation for developing brain-like neuromorphic modeling in artificial intelligence.
We applied an integrative approach using multiple methods to verify cytosine methylation in the chloroplast DNA of the multicellular brown alga Saccharina japonica. Cytosine DNA methylation is a heritable process which plays important roles in regulating development throughout the life cycle of an organism. Although methylation of nuclear DNA has been studied extensively, little is known about the state and role of DNA methylation in chloroplast genomes, especially in marine algae. Here, we have applied an integrated approach encompassing whole-genome bisulfite sequencing, methylated DNA immunoprecipitation, gene co-expression networks and photophysiological analyses to provide evidence for the role of chloroplast DNA methylation in a marine alga, the multicellular brown alga Saccharina japonica. Although the overall methylation level was relatively low in the chloroplast genome of S. japonica, gametophytes exhibited higher methylation levels than sporophytes. Gene-specific bisulfite-cloning sequencing provided additional evidence for the methylation of key photosynthetic genes. Many of them were highly expressed in sporophytes whereas genes involved in transcription, translation and biosynthesis were strongly expressed in gametophytes. Nucleus-encoded photosynthesis genes were co-expressed with their chloroplast-encoded counterparts potentially contributing to the higher photosynthetic performance in sporophytes compared to gametophytes where these co-expression networks were less pronounced. A nucleus-encoded DNA methyltransferase of the DNMT2 family is assumed to be responsible for the methylation of the chloroplast genome because it is predicted to possess a plastid transit peptide.
The Developing Belief Network is a global research collaborative studying religious development in diverse social-cultural settings, with a focus on the intersection of cognitive mechanisms and cultural beliefs and practices in early and middle childhood. The current manuscript describes the study protocol for the network's second wave of data collection, which aims to further explore the development and diversity of religious cognition and behavior using a multi-time point approach. This protocol is designed to investigate three key research questions-how children represent and reason about religious and supernatural agents, how children represent and reason about religion as an aspect of social identity, and how religious and supernatural beliefs are transmitted within and between generations-via a set of eight tasks for children between the ages of 5 and 13 years and a survey completed by their parents/caregivers. This study is being conducted in 41 distinct cultural-religious settings, spanning 16 countries and 12 written languages. In this manuscript, we provide detailed descriptions of all elements of this study protocol, and give a brief overview of the ways in which this protocol has been adapted for use in diverse religious communities. As one example of how this protocol has been implemented outside of the United States, we present Arabic- and English-language study materials for children being raised in one of the following religious traditions in Lebanon: the Druze faith, Maronite Christianity, Orthodox Christianity, Shia Islam, or Sunni Islam. We end with reflections on the challenges of developing and implementing large-scale, multi-site, multi-time point studies of child development; our approach to navigating these challenges; and our suggestions for how future researchers might learn from our experiences and build on the work presented here.