Curved ratchets improve bacteria rectification in microfluidic devices

Physical Review E American Physical Society (APS) 104:1 (2021) 014602

Authors:

Simone Coppola, Vasily Kantsler

Universal features in panarthropod inter-limb coordination during forward walking

Integrative and Comparative Biology Society for Integrative and Comparative Biology 61:2 (2021) 710-722

Abstract:

Terrestrial animals must often negotiate heterogeneous, varying environments. Accordingly, their locomotive strategies must adapt to a wide range of terrain, as well as to a range of speeds to accomplish different behavioral goals. Studies in Drosophila have found that inter-leg coordination patterns (ICPs) vary smoothly with walking speed, rather than switching between distinct gaits as in vertebrates (e.g., horses transitioning between trotting and galloping). Such a continuum of stepping patterns implies that separate neural controllers are not necessary for each observed ICP. Furthermore, the spectrum of Drosophila stepping patterns includes all canonical coordination patterns observed during forward walking in insects. This raises the exciting possibility that the controller in Drosophila is common to all insects, and perhaps more generally to panarthropod walkers. Here, we survey and collate data on leg kinematics and inter-leg coordination relationships during forward walking in a range of arthropod species, as well as include data from a recent behavioral investigation into the tardigrade Hypsibius exemplaris. Using this comparative dataset, we point to several functional and morphological features that are shared among panarthropods. The goal of the framework presented in this review is to emphasize the importance of comparative functional and morphological analyses in understanding the origins and diversification of walking in Panarthropoda.

Molecular structure of the intact bacterial flagellar basal body

Nature Microbiology Springer Nature 6:6 (2021) 712-721

Authors:

Steven Johnson, Emily J Furlong, Justin C Deme, Ashley L Nord, Joseph JE Caesar, Fabienne FV Chevance, Richard M Berry, Kelly T Hughes, Susan M Lea

A comprehensive study of biocompatibility of detonation nanodiamonds

Journal of Molecular Liquids Elsevier 332 (2021) 115763

Authors:

Gregory M Berdichevskiy, Lubov V Vasina, Sergei V Ageev, Anatolii A Meshcheriakov, Mikhail A Galkin, Robert R Ishmukhametov, Alexei V Nashchekin, Demid A Kirilenko, Andrey V Petrov, Sofia D Martynova, Konstantin N Semenov, Vladimir V Sharoyko

Abstract:

The article describes a complex study of detonation nanodiamonds (DND) aqueous dispersions. In this research, DND sample was characterised by means of IR, NMR spectroscopy, TEM, thermogravimetric analysis, size distribution, and ζ-potentials. It was shown that DND sample includes several surface groups, mainly hydroxylic, carboxylic, and carbonyl ones. Dynamic light scattering results revealed that in the concentration range C = 0.002–0.3 wt%, DND nanoparticles size is equal to 55 ± 5 nm. It was demonstrated that DND possessed weak antiradical activity, had an inhibitory effect on F1F0-ATPase activity, almost did not affect platelet aggregation, formed a stronger complex with human serum albumin (HSA) in subdomain IB (digitoxin, Kb = 20.0 ± 2.4 l·g−1) and a less strong complex in subdomain IIA (warfarin, Kb = 3.7 ± 0.1 l·g−1), inhibited the esterase activity of HSA, DND dispersions (C = 0.0012–0.15 wt%) revealed genotoxic effect towards PBMCs, did not affect cellular proliferation in the experiment with HEK293 cell line, did not reveal cytotoxic effect up to 0.01 wt%. Using DFT and MD approaches allowed us to perform a simulation of interaction between DND nanoparticle and water molecules.

A test of the cosmological principle with quasars

Astrophysical Journal Letters IOP Publishing 908:2 (2021) L51

Authors:

Nathan Secrest, Sebastian Von Hausegger, Mohamed Rameez, Roya Mohayaee, Subir Sarkar, Jacques Colin

Abstract:

We study the large-scale anisotropy of the universe by measuring the dipole in the angular distribution of a flux-limited, all-sky sample of 1.36 million quasars observed by the Wide-field Infrared Survey Explorer (WISE). This sample is derived from the new CatWISE2020 catalog, which contains deep photometric measurements at 3.4 and 4.6 μm from the cryogenic, post-cryogenic, and reactivation phases of the WISE mission. While the direction of the dipole in the quasar sky is similar to that of the cosmic microwave background (CMB), its amplitude is over twice as large as expected, rejecting the canonical, exclusively kinematic interpretation of the CMB dipole with a p-value of 5 × 10−7 (4.9σ for a normal distribution, one-sided), the highest significance achieved to date in such studies. Our results are in conflict with the cosmological principle, a foundational assumption of the concordance ΛCDM model.