The infective third stage larvae of hookworms infect their hosts by active skin invasion, and they find and recognize their hosts by the behavioural phases of activation, directed crawling, and penetration. Here we analyse the orientation of the infective larvae of the human hookworms Necator americanus and Ancylostoma duodenale when crawling on surfaces. Their behaviour differed from that of the larvae of the dog hookworm Ancylostoma caninum, but the two species also differed from each other. N. americanus crawled towards light, but A. duodenale did not. Both species migrated towards the warm ends of thermal gradients, and this response was more sensitive than in other skin-invading helminths (threshold 0.09 degrees C/cm). However, A. duodenale turned back and accumulated at higher temperatures than N. americanus [turn-back 45.7 (44.5-49.9) vs 41.5 (38.5-43.9) degrees C; accumulation 43.6 (41.6-46.0) vs 39.5 (37.9-43.0) degrees C]. In contrast to other skin-invading helminths, both species showed no chemo-orientation towards skin compounds when crawling on surfaces. This behaviour may reflect adaptations for reaching the skin surface from hairs or adhering material, but the differences in the orientation of the two species could not be attributed to differing transmission strategies.
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Sports Biomech
January 2025
Graduate School of Science and Technology, Shinshu University, Ueda, Nagano, Japan.
We aimed to investigate whether a linear relationship exists between swimming velocity and vertical body position for each stroke phase in front crawl, and to determine whether there are differences in the velocity effect among the stroke phases. Eleven male swimmers performed a 15 m front crawl at various swimming velocities. The whole-body centre of mass (CoM) was estimated from individual digital human models using inverse kinematics.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China.
Circulation
November 2024
Division of Hematology, Department of Medicine, Washington University School of Medicine, St Louis, MO. (J.L., B.B., A.S., V.K., J.C.).
Background: Ca release-activated Ca channel regulator 2A (CRACR2A) has been linked to immunodeficiency attributable to T-cell dysfunction in humans. We discovered that neutrophil CRACR2A promotes neutrophil adhesive and migratory functions by facilitating Ca mobilization and β2 integrin activation.
Methods: Myeloid-specific cracr2a conditional knockout mice and intravital microscopy were used to investigate the physiologic role of neutrophil cracr2a in neutrophil recruitment in vascular inflammation.
Biomimetics (Basel)
November 2024
Research Center of Aerospace Mechanism and Control, School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150080, China.
This article addresses the challenge of minimizing landing impacts for legged space robots during on-orbit operations. Inspired by the agility of cats, we investigate the role of forelimbs in the landing process. By identifying the kinematic chain of the cat skeleton and tracking it using animal posture estimation, we derive the cushioning strategy that cats use to handle landing impacts.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum University of Bologna, Via Massarenti 9, Bologna, 40138, Italy.
Cellular motility is essential for making and maintaining multicellular organisms throughout their lifespan. Migrating cells can move either individually or collectively by a crawling movement that links the cytoskeletal activity to the adhesion surface. In vitro stimulation by electric fields can be achieved by direct, capacitive or inductive coupled setups.
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