When Paramecium encounters positive stimuli, the membrane hyperpolarizes and ciliary beat frequency increases. We adapted an established immobilization protocol using a biological adhesive and a novel digital analysis system to quantify beat frequency in immobilized Paramecium. Cells showed low mortality and demonstrated beat frequencies consistent with previous studies. Chemoattractant molecules, reduction in external potassium, and posterior stimulation all increased somatic beat frequency. In all cases, the oral groove cilia maintained a higher beat frequency than mid-body cilia, but only oral cilia from cells stimulated with chemoattactants showed an increase from basal levels.
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http://dx.doi.org/10.1111/jeu.12153 | DOI Listing |
Cryobiology
January 2025
Laboratorio de Biotecnología de la Reproducción Animal, Facultad de Ciencias Agropecuarias, Universidad de Cuenca, EC010205, Cuenca, Ecuador.
This study evaluated the effectiveness of Percoll® density gradient centrifugation (Percoll-DGC) for selecting bull epididymal sperm prior to conventional slow (CS) or ultra-rapid (UR) freezing and its effects on sperm quality. Fifteen pooled samples from 30 epididymides (2 different samples/pool) of 15 bulls were split into two aliquots assigned to either CS or UR freezing. Samples were either selected using Percoll-DGC (40/80 %) or left non-selected (control), resulting in four pre-freezing treatments: Percoll-CS, Control-CS, Percoll-UR, and Control-UR.
View Article and Find Full Text PDFTerahertz (THz) generation via photomixing on photoconductive antenna using twin delayed chirped pulses provides a long THz pulse with a narrow bandwidth. To generate a long pulse with a broad bandwidth, we propose a new, to the best of our knowledge, method that combines two long optical pulses with opposite chirps. The pulses exhibit temporal distributions of their instantaneous frequencies with opposite slopes.
View Article and Find Full Text PDFBMJ Open
January 2025
Department of Joint Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, China
Objectives: To evaluate the association between heart rate on admission and mortality in elderly patients with hip fractures.
Design: A retrospective cohort study.
Setting: At a trauma centre in northwestern China.
Sensors (Basel)
December 2024
Key Laboratory of Science and Technology on Micro-System, Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences, Shanghai 200050, China.
Frequency-modulated continuous-wave (FMCW) radar is used to extract range and velocity information from the beat signal. However, the traditional joint range-velocity estimation algorithms often experience significant performances degradation under low signal-to-noise ratio (SNR) conditions. To address this issue, this paper proposes a novel approach utilizing the complementary ensemble empirical mode decomposition (CEEMD) combined with singular value decomposition (SVD) to reconstruct the beat signal prior to applying the FFT-Root-MUSIC algorithm for joint range and velocity estimation.
View Article and Find Full Text PDFGlucose-6-Phosphatase (G6Pase), a key enzyme in gluconeogenesis and glycogenolysis in the mammalian liver and kidney, converts glucose-6-phosphate to glucose for maintaining systemic blood glucose homeostasis during nutrient deprivation. However, its function has remained elusive in insects, which have no need for G6Pase in sugar homeostasis since they convert glucose-6-phosphate to trehalose, their main circulating sugar, via trehalose phosphate synthase (TPS1). In this study we identify an unexpected and essential requirement for G6Pase in male fertility, specifically to produce motile sperm.
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