YAP Promotes Cell Proliferation and Stemness Maintenance of Porcine Muscle Stem Cells under High-Density Condition

Muscle stem cells (MuSCs) isolated ex vivo are essential original cells to produce cultured meat. Currently, one of the main obstacles for cultured meat production derives from the limited capacity of large-scale amplification of MuSCs, especially under high-density culture condition. Here, we show that at higher cell densities, proliferation and differentiation capacities of porcine MuSCs are impaired. We investigate the roles of Hippo-YAP signaling, which is important regulators in response to cell contact inhibition. Interestingly, abundant but not functional YAP proteins are accumulated in MuSCs seeded at high density. When treated with lysophosphatidic acid (LPA), the activator of YAP, porcine MuSCs exhibit increased proliferation and elevated differentiation potential compared with control cells. Moreover, constitutively active YAP with deactivated phosphorylation sites, but not intact YAP, promotes cell proliferation and stemness maintenance of MuSCs. Together, we reveal a potential molecular target that enables massive MuSCs expansion for large-scale cultured meat production under high-density condition.

Global Hölder continuity of solutions to quasilinear equations with Morrey data

We deal with general quasilinear divergence-form coercive operators whose prototype is the [Formula: see text]-Laplacean operator. The nonlinear terms are given by Carathéodory functions and satisfy controlled growth structure conditions with data belonging to suitable Morrey spaces. The fairly non-regular boundary of the underlying domain is supposed to satisfy a capacity density condition which allows domains with exterior corkscrew property. We prove global boundedness and Hölder continuity up to the boundary for the weak solutions of such equations, generalizing this way the classical [Formula: see text]-result of Ladyzhenskaya and Ural’tseva to the settings of the Morrey spaces.

Lightening gravity-mediated dark matter

We revisit the scenario of a massive spin-2 particle as the mediator for communicating between dark matter of arbitrary spin and the Standard Model. Taking the general couplings of the spin-2 particle in the effective theory, we discuss the thermal production mechanisms for dark matter with various channels and the dark matter self-scattering. For WIMP and light dark matter cases, we impose the relic density condition and various experimental constraints from direct and indirect detections, precision measurements as well as collider experiments. We show that it is important to include the annihilation of dark matter into a pair of spin-2 particles in both allowed and forbidden regimes, thus opening up the consistent parameter space for dark matter. The benchmark models of the spin-2 mediator are presented in the context of the warped extra dimension and compared to the simplified models.

Inconsistencies between mental fatigue measures under compensatory control theories

Mental fatigue has traditionally been defined as a condition of reduced cognitive efficiency and performance, accompanied by a subjective feeling of fatigue. Even though we could expect to find associations between the three defining characteristic of mental fatigue (performance impairment, physiological deactivation and subjective fatigue), research has shown that the emergence of inconsistencies between measures is more frequent than one might expect: people proved capable of maintaining adequate performance levels even after having declared themselves fatigued. This could be explained under the compensatory control mechanism models, which state that humans are able to provide additional resources under demanding conditions, but only at the expense of psychophysiological cost and subjective fatigue. We tested this explanation by manipulating task complexity and time performing a simulated air-traffic control task. We collected psychophysiological, performance and subjective data. A decrease in pupil size was seen in the low-aircraft-density condition, while pupil size remained constant in the high-aircraft-density condition. Participants’ task performance was optimal in both conditions, though they showed an increase in subjective feelings of fatigue, especially in the high-complexity task condition. Thus, complexity seemed to trigger compensatory mechanisms, which reallocated extra resources that physiologically activated participants in order to deal with a higher complexity task, whereas subjective fatigue could be acting as a signal to the organism of impending resource depletion. Our findings support compensatory control theories and offer an explanation of inconsistencies between fatigue measures. Further research on compensatory mechanisms is needed to enable better management of fatigue effects to prevent work-related accidents.

Effect of architectural adjustments on pedestrian flow at bottleneck

In the last decades, a series of terrible accidents happened within pedestrian crowds, which makes crowd dynamic a significant issue to be investigated. Literature reviews show that pedestrian flow presents different features within different architectural layout. In this paper, pedestrian movement properties at bottleneck are studied by carrying out series of experiments under laboratory condition. The influence of door sizes and exit locations on pedestrian crowd flow is investigated. It was found that larger door width resulted in shorter evacuation time and faster flow rate. By comparing the fundamental diagram among crowd evacuation, the average velocity increases as the width increases under the same density condition. Interestingly, the influence of the boundary layer, as well as the effective width on pedestrian crowd dynamic, was clearly observed. Our results suggest that the combination of exit width and location resulted in a synergistic effect, but the exit widths gradually became the most important factor influencing the flow rate.

Light-induced assembly of living bacteria with honeycomb substrate

Some bacteria are recognized to produce useful substances and electric currents, offering a promising solution to environmental and energy problems. However, applications of high-performance microbial devices require a method to accumulate living bacteria into a higher-density condition in larger substrates. Here, we propose a method for the high-density assembly of bacteria (106 to 107 cells/cm2) with a high survival rate of 80 to 90% using laser-induced convection onto a self-organized honeycomb-like photothermal film. Furthermore, the electricity-producing bacteria can be optically assembled, and the electrical current can be increased by one to two orders of magnitude simply by increasing the number of laser irradiations. This concept can facilitate the development of high-density microbial energy conversion devices and provide new platforms for unconventional environmental technology.

The Mutual Singularity of Harmonic Measure and Hausdorff Measure of Codimension Smaller than One

Let $\Omega \subset{\mathbb{R}}^{n+1}$ be open and let $E\subset \partial \Omega $ with $0<{\mathcal{H}}^s(E)<\infty $, for some $s\in (n,n+1)$, satisfy a local capacity density condition. In this paper it is shown that the harmonic measure cannot be mutually absolutely continuous with the Hausdorff measure ${\mathcal{H}}^s$ on $E$. This answers a question of Azzam and Mourgoglou, who had proved the same result under the additional assumption that $\Omega $ is a uniform domain.