Collective cell migration, the simultaneous movement of multiple cells that are connected by cell-cell adhesion, is ubiquitous in development, tissue repair, and tumor metastasis [1, 2]. It has been hypothesized that the directionality of cell movement during collective migration emerges as a collective property [3, 4]. Here we determine how movement directionality is established in collective ...

This work is focused on the problem of identifying interactions between complex dynamical oscillatory processes. Discovering relationships in complex systems plays an important role in the process of understanding how subsystems cooperate to create complicated behavior. There are two main problems in interaction analysis: directionality analysis and synchronization detection. Synchronization is...

Auditory neurons in the inferior colliculus (IC) show remarkable selectively in that they can distinguish between complex sounds that have identical spectral energy but different temporal structure, such as frequency modulations (FMs) that sweep either upward or downward. Extracellular recordings show that blocking inhibition locally reduces or eliminates response selectivity, suggesting that s...

Protein motors, such as kinesins and dyneins, bind to a microtubule and travel along it in a specific direction. Previously, it was thought that the directionality for a given motor was constant in the absence of an external force. However, the directionality of the kinesin-5 Cin8 was recently found to change as the number of motors that bind to the same microtubule is increased. Here, we intro...

Enhancement of transcription by a splicing-competent intron is an evolutionarily conserved feature among eukaryotes. The molecular mechanism underlying the phenomenon, however, is not entirely clear. Here we show that the intron is an important regulator of promoter directionality. Employing strand-specific transcription run-on (TRO) analysis, we show that the transcription of mRNA is favored o...

In optimality theory, the grammar evaluates candidate outputs in parallel against a hierarchy of ranked, violable constraints. One of the main advantages of this framework is its ability to capture nonlocal dependencies straightforwardly, obviating the need to build the ill-formed intermediate structures that are sometimes inevitable in bottom-up approaches. A major challenge for parallel evalu...

The directional selectivity of amacrine and ganglion cells was studied using conventional intracellular recording techniques and drug application in the superfused retina-eyecup preparation of the tiger salamander. Baclofen, a GABAB receptor agonist, enhanced normal directional responses in some directionally selective third-order neurons. In about 30% of the cells that were not normally direct...

Bertrand Russell famously argued that causation is not part of the fundamental physical description of the world, describing the notion of cause as “a relic of a bygone age” (Russell, 1913, p. 1). This paper assesses one of Russell’s arguments for this conclusion: the ‘Directionality Argument’, which holds that the time symmetry of fundamental physics is inconsistent with the time asymmetry of ...

In design and analysis, standard references assume the pedestrian flow as unidirectional. In reality however, pedestrian flow is usually bi-directional. The main question pursued in this paper is that whether the main characteristics of pedestrian flow the same under uni- and bi-directional conditions. In order to achieve this goal, effect of bi-directional stream is inv...