We develop a stochastic metapopulation model that accounts for spatial structure as well as within patch dynamics. Using a deterministic approximation derived from a functional law of large numbers, we develop conditions for extinction and persistence of the metapopulation in terms of the birth, death and migration parameters. Interestingly, we observe the Allee effect in a metapopulation comprising two patches of greatly different sizes, despite there being decreasing patch specific per-capita birth rates. We show that the Allee effect is due to the way the migration rates depend on the population density of the patches.
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http://dx.doi.org/10.1016/j.mbs.2013.11.001 | DOI Listing |
ACS Biomater Sci Eng
January 2025
Luzhou Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou 646000, China.
Oral ulcer wounds are difficult to heal due to bacterial infections, persistent inflammatory responses, and excessive reactive oxygen species (ROS). Therefore, the elimination of bacteria, removal of ROS, and reduction of inflammation are prerequisites for the treatment of mouth ulcer wounds. In this study, oligomeric proanthocyanidins (OPC) and 3-(aminomethyl)phenylboronic acid-modified hyaluronic acid (HP) were used to form polymer gels through dynamic covalent borate bonds.
View Article and Find Full Text PDFSci Rep
January 2025
Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
Observing quantum mechanical characteristics in biological processes is a surprising and important discovery. One example, which is gaining more experimental evidence and practical applications, is the effect of weak magnetic fields with extremely low frequencies on cells, especially cancerous ones. In this study, we use a mathematical model of ROS dynamics in cancer cells to show how ROS oscillatory patterns can act as a resonator to amplify the small effects of the magnetic fields on the radical pair dynamics in mitochondrial Complex III.
View Article and Find Full Text PDFFront Neurosci
January 2025
The Key Laboratory of Anesthesia and Organ Protection, The Key Laboratory of Brain Science, Zunyi Medical University, Zunyi, China.
Background: The ventrolateral preoptic nucleus (VLPO) is a crucial regulator of sleep, and its neurons are implicated in both sleep-wake regulation and anesthesia-induced loss of consciousness. Propofol (PRO), a widely used intravenous anesthetic, modulates the activity of VLPO neurons, but the underlying mechanisms, particularly the role of dopaminergic receptors, remain unclear.
Objective: This study aimed to investigate the effects of PRO on NA (-) neurons in the VLPO and to determine the involvement of D1 and D2 dopaminergic receptors in mediating these effects.
Curr Biol
January 2025
Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA 94305, USA. Electronic address:
Microtubules (MTs) are intrinsically dynamic polymers. In neurons, staggered individual microtubules form stable, polarized acentrosomal MT arrays spanning the axon and dendrite to support long-distance intracellular transport. How the stability and polarity of these arrays are maintained when individual MTs remain highly dynamic is still an open question.
View Article and Find Full Text PDFMed Image Anal
January 2025
Department of Radiology, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Southern Medical University, Guangzhou, China. Electronic address:
Deep multiple instance learning (MIL) pipelines are the mainstream weakly supervised learning methodologies for whole slide image (WSI) classification. However, it remains unclear how these widely used approaches compare to each other, given the recent proliferation of foundation models (FMs) for patch-level embedding and the diversity of slide-level aggregations. This paper implemented and systematically compared six FMs and six recent MIL methods by organizing different feature extractions and aggregations across seven clinically relevant end-to-end prediction tasks using WSIs from 4044 patients with four different cancer types.
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