The effect of shape asymmetry of microswimmers on their adsorption capacity at confining channel walls is studied by a simple dumbbell model. For a shape polarity of a forward-swimming cone, like the stroke-averaged shape of a sperm, extremely long wall retention times are found, caused by a nonvanishing component of the propulsion force pointing steadily into the wall, which grows exponentially with the self-propulsion velocity and the shape asymmetry. A direct duality relation between shape asymmetry and wall curvature is proposed and verified. Our results are relevant for the design microswimmer with controlled wall-adhesion properties. In addition, we confirm that pressure in active systems is strongly sensitive to the details of the particle-wall interactions.
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http://dx.doi.org/10.1103/PhysRevE.91.050302 | DOI Listing |
Fem Econ
October 2023
National Council of Applied Economic Research, New Delhi, Delhi, India.
While increased access to household assets has been shown to improve older individuals' autonomy and bargaining power at home, the role of gender hierarchy in shaping differential impacts of household assets has received far less attention. This article explores the gender asymmetry in the association of older people's (age 60 years or more) decision-making power at home and survival probability with their ownership of and managerial control over agricultural land in rural India. Using data from the India Human Development Survey, results find that in multi-generational households, landownership at the household level is associated with higher decision-making power and survival probability for older men but not for older women.
View Article and Find Full Text PDFJ Evol Biol
January 2025
Laboratorio de Ecotono, Instituto de Investigaciones em Biodiversidad y Medioambiente (INIBIOMA), CONICET- Universidad Nacional del Comahue, San Carlos de Bariloche, Río Negro, Argentina.
Modularity and developmental (in)stability have the potential to influence phenotype production and, consequently, the evolutionary trajectories of species. Depending on the environmental factors involved and the buffering capacity of an organism, different developmental outcomes are expected. Cactophilic Drosophila species provide an established eco-evolutionary model with well-studied ecological conditions, making them ideal for studying these phenomena.
View Article and Find Full Text PDFBeilstein J Org Chem
January 2025
Institute of Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands.
Polysarcosine emerges as a promising alternative to polyethylene glycol (PEG) in biomedical applications, boasting advantages in biocompatibility and degradability. While the self-assembly behavior of block copolymers containing polysarcosine-containing polymers has been reported, their potential for shape transformation remains largely untapped, limiting their versatility across various applications. In this study, we present a comprehensive methodology for synthesizing, self-assembling, and transforming polysarcosine-poly(benzyl glutamate) block copolymers, resulting in the formation of bowl-shaped vesicles, disks, and stomatocytes.
View Article and Find Full Text PDFJ Acoust Soc Am
January 2025
Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland 20742, USA.
Threshold estimation procedures are widely used to measure the stimulus level corresponding to a specified probability of response. The weighted up-and-down procedure, familiar to many due to its use in standard pure-tone audiometry, allows the experimenter to target any probability of response by using different ascending and descending step sizes. Unfortunately, thresholds have a signed mean error that made using weighted staircases inadvisable.
View Article and Find Full Text PDFAnat Rec (Hoboken)
January 2025
Muséum national d'Histoire naturelle, Centre de Recherche en Paléontologie-Paris (CR2P), UMR 7207 MNHN/CNRS/UPMC, Sorbonne Université, Paris, France.
Pangolins are the most heavily trafficked mammals in the world, largely because of the high demand for their keratinous scales from the traditional Chinese medicine market. While seizures of pangolin material are largely composed of isolated scales, efficient approaches to reach species-level identification are missing. This mostly originates from the lack of comparative studies on the shape of pangolin scales, resulting in knowledge gaps on the imbricated effects of serial, ontogenetic, and evolutionary variations.
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