Inspired by recent experiments on the dynamics of particles and polymers in artificial cytoskeletons and in cells, we introduce a modified Langevin equation for a particle in an environment that is a viscoelastic medium and that is brought out of equilibrium by the action of active fluctuations caused by molecular motors. We show that within such a model, the motion of a free particle crosses over from superdiffusive to subdiffusive as observed for tracer particles in an in vitro cytoskeleton or in a cell. We investigate the dynamics of a particle confined by a harmonic potential as a simple model for the motion of the tethered head of kinesin-1. We find that the probability that the head is close to its binding site on the microtubule can be enhanced by a factor of two due to active forces. Finally, we study the dynamics of a particle in a double well potential as a model for the dynamics of DNA-hairpins. We show that the active forces effectively lower the potential barrier between the two minima and study the impact of this phenomenon on the zipping/unzipping rate.
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Arch Environ Contam Toxicol
January 2025
Center for Fisheries, Aquaculture and Aquatic Sciences, School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA.
Aquatic systems are impacted by temperature fluctuations which can alter the toxicity of pesticides. Increased temperatures related to climate change have elevated pest activity, resulting in an escalation of pesticide use. One such pesticide class, pyrethroids, has replaced the use of several banned pesticides due to its low mammalian toxicity.
View Article and Find Full Text PDFBrain
January 2025
Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
The neurobiological mechanisms driving the ictal-interictal fluctuations and the chronification of migraine remain elusive. We aimed to construct a composite genetic-microRNA model that could reflect the dynamic perturbations of the disease course and inform the pathogenesis of migraine. We prospectively recruited four groups of participants, including interictal episodic migraine (i.
View Article and Find Full Text PDFMol Cell
January 2025
Department of Genetics and Development and Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA. Electronic address:
Cells integrate metabolic information into core molecular processes such as transcription to adapt to environmental changes. Chromatin, the physiological template of the eukaryotic genome, has emerged as a sensor and rheostat for fluctuating intracellular metabolites. In this review, we highlight the growing list of chromatin-associated metabolites that are derived from diverse sources.
View Article and Find Full Text PDFWater Res
January 2025
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China. Electronic address:
The microalgal-bacterial consortium (MBC) system is recognized as an advanced approach for nitrogen and phosphorus removal in wastewater treatment. However, the influence of microalgae on bacterial community dynamics and niche differentiation across varying seasonal conditions remains unexplored. In this study, we established a pilot-scale continuous-flow MBC system to disentangle, for the first time, the impact of microalgae on seasonal bacterial community succession by conducting monthly time-series sampling over a full seasonal cycle.
View Article and Find Full Text PDFJ Physiol Sci
December 2024
Laboratory of Exercise Biochemistry and Neuroendocrinology, Institute of Health and Sport Sciences, University of Tsukuba, Ibaraki 305-8574, Japan; Sport Neuroscience Division, Advanced Research Initiative for Human High Performance (ARIHHP), Institute of Health and Sport Sciences, University of Tsukuba, Ibaraki 305-8574, Japan. Electronic address:
Developing strategies to enhance cardiac vagal activity (CVA) is essential for improving mood and managing stress. Although hypoxia inhalation may boost CVA, the optimal acute hypoxic conditions remain unclear. Therefore, we aimed to achieve a comprehensive understanding of the hypoxic conditions required to improve CVA and mood following hypoxia.
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