scholarly journals Morphological transitions of active Brownian particle aggregates on porous walls

Soft Matter ◽  
2020 ◽  
Vol 16 (31) ◽  
pp. 7250-7255 ◽  
Author(s):  
Suchismita Das ◽  
Raghunath Chelakkot

Cluster of aggregated active Brownian particles (ABPs) undergoes morphological transition on porous walls.

Soft Matter ◽  
2020 ◽  
Vol 16 (20) ◽  
pp. 4776-4787 ◽  
Author(s):  
Amir Shee ◽  
Abhishek Dhar ◽  
Debasish Chaudhuri

A polymer-mapping of active Brownian particle (ABP)-trajectories, and exact calculation of the moments of dynamical variables provide insights into the mechanical crossovers in polymers with length, and related dynamical crossovers in ABP-motion.


2021 ◽  
Vol 18 (177) ◽  
Author(s):  
Harvey L. Devereux ◽  
Colin R. Twomey ◽  
Matthew S. Turner ◽  
Shashi Thutupalli

We study the collective dynamics of groups of whirligig beetles Dineutus discolor (Coleoptera: Gyrinidae) swimming freely on the surface of water. We extract individual trajectories for each beetle, including positions and orientations, and use this to discover (i) a density-dependent speed scaling like v ∼ ρ − ν with ν ≈ 0.4 over two orders of magnitude in density (ii) an inertial delay for velocity alignment of approximately 13 ms and (iii) coexisting high and low-density phases, consistent with motility-induced phase separation (MIPS). We modify a standard active Brownian particle (ABP) model to a corralled ABP (CABP) model that functions in open space by incorporating a density-dependent reorientation of the beetles, towards the cluster. We use our new model to test our hypothesis that an motility-induced phase separation (MIPS) (or a MIPS like effect) can explain the co-occurrence of high- and low-density phases we see in our data. The fitted model then successfully recovers a MIPS-like condensed phase for N = 200 and the absence of such a phase for smaller group sizes N = 50, 100.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Ganesh Shete ◽  
Shyamprasad Karagadde ◽  
Atul Srivastava

AbstractThe present work reports the morphological transition during solidification of a non-metallic system. Pure magnesium silicate (Mg2SiO4) is chosen as the model material and the solidification experiments have been conducted under purely non-contact conditions using the principles of aerodynamic levitation. The influence of the undercooling and cooling rates on the surface features observed in the solidified samples is investigated. Levitation experiments have been performed for different samples, which are solidified for a range of undercooling levels between 360 to 1100° C. In order to understand and report the morphological transitions, solidified samples have been observed using scanning electron microscopy, which showed the formation of highly branched faceted microstructure for an undercooling regime of 360–800° C, and non-dendritic microstructure for even higher undercooling regime of 800–1100° C. Further experiments performed on this non-metallic system for different cooling rates also suggested that, regardless of the cooling rate, lower undercooling leads to branched faceted features, whereas higher undercooling results into unbranched facets. The methodology and instrumentation provide unique capabilities to probe the behavior of materials at high temperatures.


mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Robin C. May ◽  
Arturo Casadevall

ABSTRACT For pathogenic microbes to survive ingestion by macrophages, they must subvert powerful microbicidal mechanisms within the phagolysosome. After ingestion, Candida albicans undergoes a morphological transition producing hyphae, while the surrounding phagosome exhibits a loss of phagosomal acidity. However, how these two events are related has remained enigmatic. Now Westman et al. (mBio 9:e01226-18, 2018, https://doi.org/10.1128/mBio.01226-18) report that phagosomal neutralization results from disruption of phagosomal membrane integrity by the enlarging hyphae, directly implicating the morphological transition in physical damage that promotes intracellular survival. The C. albicans intracellular strategy shows parallels with another fungal pathogen, Cryptococcus neoformans, where a morphological changed involving capsular enlargement intracellularly is associated with loss of membrane integrity and death of the host cell. These similarities among distantly related pathogenic fungi suggest that morphological transitions that are common in fungi directly affect the outcome of the fungal cell-macrophage interaction. For this class of organisms, form determines fate in the intracellular environment.


2013 ◽  
Vol 392 (19) ◽  
pp. 4210-4215 ◽  
Author(s):  
Wei Guo ◽  
Can-Jun Wang ◽  
Lu-Chun Du ◽  
Dong-Cheng Mei

2020 ◽  
Vol 125 (17) ◽  
Author(s):  
Claudio B. Caporusso ◽  
Pasquale Digregorio ◽  
Demian Levis ◽  
Leticia F. Cugliandolo ◽  
Giuseppe Gonnella

Soft Matter ◽  
2018 ◽  
Vol 14 (18) ◽  
pp. 3581-3589 ◽  
Author(s):  
Eric W. Burkholder ◽  
John F. Brady

We generalize the active Brownian particle model to account for hydrodynamic interactions.


Antibiotics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Olena P. Ishchuk ◽  
Olov Sterner ◽  
Ulf Ellervik ◽  
Sophie Manner

The opportunistic human fungal pathogen Candida albicans relies on cell morphological transitions to develop biofilm and invade the host. In the current study, we developed new regulatory molecules, which inhibit the morphological transition of C. albicans from yeast-form cells to cells forming hyphae. These compounds, benzyl α-l-fucopyranoside and benzyl β-d-xylopyranoside, inhibit the hyphae formation and adhesion of C. albicans to a polystyrene surface, resulting in a reduced biofilm formation. The addition of cAMP to cells treated with α-l-fucopyranoside restored the yeast-hyphae switch and the biofilm level to that of the untreated control. In the β-d-xylopyranoside treated cells, the biofilm level was only partially restored by the addition of cAMP, and these cells remained mainly as yeast-form cells.


Sign in / Sign up

Export Citation Format

Share Document