Are microtubules tension sensors? Hamant, Olivier; Inoue, Daisuke; Bouchez, David ...
Nature communications,
05/2019, Volume:
10, Issue:
1
Journal Article
Peer reviewed
Open access
Mechanical signals play many roles in cell and developmental biology. Several mechanotransduction pathways have been uncovered, but the mechanisms identified so far only address the perception of ...stress intensity. Mechanical stresses are tensorial in nature, and thus provide dual mechanical information: stress magnitude and direction. Here we propose a parsimonious mechanism for the perception of the principal stress direction. In vitro experiments show that microtubules are stabilized under tension. Based on these results, we explore the possibility that such microtubule stabilization operates in vivo, most notably in plant cells where turgor-driven tensile stresses exceed greatly those observed in animal cells.
The spread of intelligent transportation systems in urban cities has caused heavy computational loads, requiring a novel architecture for managing large-scale traffic. In this study, we develop a ...method for globally controlling traffic signals arranged on a square lattice by means of a quantum annealing machine, namely the D-Wave quantum annealer. We first formulate a signal optimization problem that minimizes the imbalance of traffic flows in two orthogonal directions. Then we reformulate this problem as an Ising Hamiltonian, which is compatible with quantum annealers. The new control method is compared with a conventional local control method for a large 50-by-50 city, and the results exhibit the superiority of our global control method in suppressing traffic imbalance over wide parameter ranges. Furthermore, the solutions to the global control method obtained with the quantum annealing machine are better than those obtained with conventional simulated annealing. In addition, we prove analytically that the local and the global control methods converge at the limit where cars have equal probabilities for turning and going straight. These results are verified with numerical experiments.
The reliability and small size of solid state scanners makes them ideal for LIDAR. We fabricated and demonstrated the successful operation of an optical scanner using silicon photonics integrated ...circuit technology. The scanner comprises a ring resonator multiplexer and a number of grating arrays, and employs a beam switching method, which means that the scanner is movement-free. The multiplexer determines the optical path and light is emitted from the selected grating. The scanning angle obtained was 6 degrees. LIDAR sensors can be used in automotive applications for automated cruising.
For Development of Nasal Formulations Inoue, Daisuke
Journal of Pharmaceutical Science and Technology, Japan,
2021/07/01, Volume:
81, Issue:
3
Journal Article
The D-Wave quantum annealer has emerged as a novel computational architecture that is attracting significant interest, but there have been only a few practical algorithms exploiting the power of ...quantum annealers. Here we present a model predictive control (MPC) algorithm using a quantum annealer for a system allowing a finite number of input values. Such an MPC problem is classified as a non-deterministic polynomial-time-hard combinatorial problem, and thus real-time sequential optimization is difficult to obtain with conventional computational systems. We circumvent this difficulty by converting the original MPC problem into a quadratic unconstrained binary optimization problem, which is then solved by the D-Wave quantum annealer. Two practical applications, namely stabilization of a spring-mass-damper system and dynamic audio quantization, are demonstrated. For both, the D-Wave method exhibits better performance than the classical simulated annealing method. Our results suggest new applications of quantum annealers in the direction of dynamic control problems.
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•Highly efficient enrichment of PHA-accumulating bacteria within 2 d was studied.•Operating conditions of aerobic dynamic discharge process were optimized.•Mixed microbial culture ...under optimum conditions can store up to 68.4 wt% PHA.•Dechloromonas and Zoogloea were major PHA-accumulating bacteria enriched.
The aerobic dynamic discharge (ADD) process has the potential to reduce the enrichment period of polyhydroxyalkanoates (PHA)-accumulating bacteria in PHA production using mixed microbial cultures (MMCs). This study aimed to efficiently enrich PHA-accumulating bacteria from activated sludge within a fixed period of 2 d by optimizing operating conditions of the ADD process. Based on the results, enrichment with separate feeding of carbon and nutrients in the feast and famine phases, respectively, and a settling duration of 10 min after the feast phase in the sequencing batch cycle for 12 h was found to be optimal. The MMC enriched at optimum conditions could store as much as 68.4 wt% of PHA. Dechloromonas and Zoogloea were identified as potential PHA-accumulating bacteria responsible for enhancing PHA accumulation ability in the enriched MMC. The optimized ADD process will facilitate the consecutive use of daily generated waste activated sludge for PHA production.
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•CH4 production during anaerobic digestion under NH4+ or NaCl stress was explored.•Common tolerable levels of NH4+ and NaCl for CH4 production were identified.•Propionate regulates ...CH4 production under inhibitory conditions.•Candidatus Brevefilum is a propionate degrader enabling efficient CH4 production.•Methanothrix appeared to be tolerant to 5 g NH4-N/L and 30 g/L NaCl.
Ammonium (NH4+) and salinity are major inhibitors of CH4 production in anaerobic digestion. This study evaluated their inhibitory effects on CH4 production and explored the key populations for efficient CH4 production under high NH4+ and NaCl concentrations to understand their inhibition mechanisms. Comparative batch experiments for mesophilic anaerobic digestion were conducted using three seeding sludges under different concentrations of NH4+ (1–5 gNH4-N/L) and NaCl (10–30 g/L). Although all sludges tolerated 3 gNH4-N/L and 10 g/L NaCl, NH4+ or NaCl concentrations higher than these substantially reduced CH4 production, depending on the seeding sludge, primarily by impairing the initial hydrolysis and methanogenesis steps. In addition, propionate was found to be a deterministic factor affecting CH4 production. Based on microbial community analysis, Candidatus Brevefilum was identified as a potential syntrophic propionate-oxidizing bacterium that facilitates the mitigation of propionate accumulation, allowing the maintenance of unaffected CH4 production under high inhibitory conditions.
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