Related papers: Phototactic Decision-Making by Micro-Algae
In this study, we analyze the bioconvection in a suspension of phototactic algae that exhibits anisotropic scattering. The top layer of the suspension is illuminated by oblique collimated irradiation. During the study, the bottom boundary…
The primary objective of this article is to explore how rotation influences the initiation of phototactic bioconvection. This investigation is conducted through the application of linear stability theory to a suspension composed of…
A simple model is studied for the chemotactic movement of biological cells in the presence of a periodic chemical wave. It incorporates the feature of adaptation that may play an important role in allowing for ``rectified" chemotaxis:…
In Nature there are significant relationships known between microorganisms from two kingdoms of life, as in the supply of vitamin B$_{12}$ by bacteria to algae. Such interactions motivate general investigations into the spatio-temporal…
Eukaryotic swimming cells such as spermatozoa, algae or protozoa use flagella or cilia to move in viscous fluids. The motion of their flexible appendages in the surrounding fluid induces propulsive forces that balance with the viscous drag…
The onset of light-induced bioconvection via linear stability theory is investigated qualitatively for a suspension of phototactic algae. The forward scattering algal suspension is uniformly illuminated by both diffuse and oblique…
The impact of rotation on the bio-convective instability in a phototactic algal suspension is investigated through a linear stability analysis in this article. The study primarily focuses on the suspension's phototactic behavior, which…
When attracted by a stimulus (e. g. light), microswimmers can build up very densely at a constriction and thus cause clogging. The micro-alga \textit{Chlamydomonas Reinhardtii} is used here as a model system to study this phenomenon. Its…
Light gradient can allow many motile photosynthetic microorganisms to bias their motion towards moderate light (positive phototaxis) or away from intense light (negative phototaxis). The proposed work presents the penetrative phototactic…
In this study, we aim to explore the behavior of microorganisms in response to natural lighting conditions, considering the off-normal angles at which the sun strikes the Earth's surface. To achieve this, we investigate the effect of…
How the cells break symmetry and organize their edge activity to move directionally is a fun- damental question in cell biology. Physical models of cell motility commonly rely on gradients of regulatory factors and/or feedback from the…
A suspension of gyrotactic microalgae Chlamydomonas augustae swimming in a cylindrical water vessel in solid-body rotation is studied. Our experiments show that swimming algae form an aggregate around the axis of rotation, whose intensity…
Chlamydomonas shows both positive and negative phototaxis. It has a single eyespot near its equator and as the cell rotates during forward motion the light signal received by the eyespot varies. We use a simple mechanical model of…
We study the distribution of swimming micro-organisms advected by a model turbulent flow and attracted towards a localised light source through phototaxis. It is shown that particles aggregate along a dynamical attractor with fractal…
Many microorganisms, with phytoplankton and zooplankton as prominent examples, display phototactic behaviour, that is, the ability to perform directed motion within a light gradient. Here we experimentally demonstrate that sensing of light…
We study the effect of inhomogeneous environments on the swimming direction of the microalgae \textit{Chlamydomonas Reinhardtii} (CR) in the presence of a light stimulus. Positive or negative phototaxis describe the ability of…
Active fluids can develop spontaneous flow instabilities and complex patterns. However, spatio-temporal control of active particles has remained challenging, despite its relevance in biological and applied contexts. Here, we harnessed…
Gyrotactic algae are bottom heavy, motile cells whose swimming direction is determined by a balance between a buoyancy torque directing them upwards and fluid velocity gradients. Gyrotaxis has, in recent years, become a paradigmatic model…
We use moving light patterns to control the motion of {\it Escherichia coli} bacteria whose motility is photo-activated. Varying the pattern speed controls the magnitude and direction of the bacterial flux, and therefore the accumulation of…
Living microorganisms are capable of a tactic response to external stimuli by swimming towards or away from the stimulus source; they do so by adapting their tactic signal transduction pathways to the environment. Their self-motility thus…