temporal interactions
Recently Published Documents

What is a human being? Some might answer this question by referring to a biological body, growing from genetic information passed on through generations. Others refer to a mind, developed from infancy to adulthood, expressing itself self-aware and intelligently. Few will argue that a human being could exist without one or the other, but many disagree on their relative contribution. Does the conscious mind emerge solely from a single physical body? Is the developing body shaped purely by biological predetermination? I propose that the formation of individual human beings is subject to an environment that envelops both, the physical and mental realms. This environment is here referred to as story-verse of humanity. It is an ecosystem that emerged from biological activity but grew and evolved into an interactive space that includes temporal interactions, such as created by nervous system activity. The emerging story-verse gives rise to persistent hyperobjects, including individual human beings, whose stories perpetuate themselves via physical and mental representations. The story-verse is a real physics realm that includes the four fundamental interactions described by particle physics, but additionally requires higher-order fundamental forces that facilitate interactions between the physical and mental realm.

This chapter examines ensemble dynamics and time consciousness in indeterminate music, using John Cage’s Concert for Piano and Orchestra (1957–8) as a case study. Drawing on interviews and observational studies undertaken with the experimental music ensemble Apartment House, I examine the role of temporal indeterminacy in the socio-musical interactions that characterize performance, and its implications for the musicians’ experiences. In doing so, the chapter makes a broader contribution in its consideration of the ways in which issues of authorship and authority are negotiated in such temporal interactions, and how the dynamics of these negotiations present a sociality based on a ‘separate togetherness’, whereby performers play together (out of time) with one another.

AbstractLineage commitment and differentiation is driven by the concerted action of master transcriptional regulators at their target chromatin sites. Multiple efforts have characterized the key transcription factors (TFs) that determine the various hematopoietic lineages. However, the temporal interactions between individual TFs and their chromatin targets during differentiation and how these interactions dictate lineage commitment remains poorly understood. Here we perform dense, daily, temporal profiling of chromatin accessibility (DNase I-seq) and gene expression changes (total RNA-seq) along ex vivo human erythropoiesis to comprehensively define developmentally regulated DNase I hypersensitive sites (DHSs) and transcripts. We link both distal DHSs to their target gene promoters and individual TFs to their target DHSs, revealing that the regulatory landscape is organized in distinct sequential regulatory modules that regulate lineage restriction and maturation. Finally, direct comparison of transcriptional dynamics (bulk and single-cell) and lineage potential between erythropoiesis and megakaryopoiesis uncovers differential fate commitment dynamics between the two lineages as they exit the stem and progenitor stage. Collectively, these data provide insights into the temporally regulated synergy of the cis- and the trans-regulatory components underlying hematopoietic lineage commitment and differentiation.

Abstract The apical hook is indispensable for protecting the delicate shoot apical meristem while dicot seedlings emerge from soil after germination in darkness. The development of the apical hook is co-ordinately regulated by multiple phytohormones and environmental factors. Yet, a holistic understanding of the spatial–temporal interactions between different phytohormones and environmental factors remains to be achieved. Using a chemical genetic approach, we identified kinetin riboside, as a proxy of kinetin, which promotes apical hook development of Arabidopsis thaliana in a partially ethylene-signaling-independent pathway. Further genetic and biochemical analysis revealed that cytokinin is able to regulate apical hook development via post-transcriptional regulation of the PHYTOCHROME INTERACTING FACTORs (PIFs), together with its canonical roles in inducing ethylene biosynthesis. Dynamic observations of apical hook development processes showed that ETHYLENE INSENSITVE3 (EIN3) and EIN3-LIKE1 (EIL1) are necessary for the exaggeration of hook curvature in response to cytokinin, while PIFs are crucial for the cytokinin-induced maintenance of hook curvature in darkness. Furthermore, these two families of transcription factors display divergent roles in light-triggered hook opening. Our findings reveal that cytokinin integrates ethylene signaling and light signaling via EIN3/EIL1 and PIFs, respectively, to dynamically regulate apical hook development during early seedling development.

AbstractWhen describing complex interconnected systems, one often has to go beyond the standard network description to account for generalized interactions. Here, we establish a unified framework to simplify the stability analysis of cluster synchronization patterns for a wide range of generalized networks, including hypergraphs, multilayer networks, and temporal networks. The framework is based on finding a simultaneous block diagonalization of the matrices encoding the synchronization pattern and the network topology. As an application, we use simultaneous block diagonalization to unveil an intriguing type of chimera states that appear only in the presence of higher-order interactions. The unified framework established here can be extended to other dynamical processes and can facilitate the discovery of emergent phenomena in complex systems with generalized interactions.