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Theoretical models suggest that the mean time to extinction scales with habitat size through either exponential or power law relationships, depending on demographic and environmental stochasticity. Despite extensive theoretical work, empirical validation of these scaling relationships is limited. Here, we report a microcosm study of Daphnia magna populations in experimental chambers consisting of 1, 2, 4, 8, 16, or 32 patches, with a total of 35 populations monitored daily until extinction. We tested the scaling of extinction time with patch count using nonlinear regression models for both exponential and power law functions, comparing model fit with mean squared error. Overall, the data supported the power law over an exponential relationship (bootstrapped ) although the difference between the models is not evident when comparing some treatment levels. Our experiment provides the first empirical test of long-standing theoretical predictions and lays a foundation for future studies to expand the understanding of extinction dynamics in ecological systems.
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http://dx.doi.org/10.1111/ele.70178 | DOI Listing |
RSC Adv
September 2025
Laboratory of Spectroscopic Characterization and Optical Materials, Faculty of Sciences, University of Sfax B.P. 1171 3000 Sfax Tunisia
Lithium metavanadate (LiVO) is a material of growing interest due to its monoclinic 2/ structure, which supports efficient lithium-ion diffusion through one-dimensional channels. This study presents a detailed structural, electrical, and dielectric characterization of LiVO synthesized a solid-state reaction, employing X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and impedance/dielectric spectroscopy across a temperature range of 473-673 K and frequency range of 10 Hz to 1 MHz. XRD and Rietveld refinement confirmed high crystallinity and single-phase purity with lattice parameters = 10.
View Article and Find Full Text PDFThe distinction between civilians and combatants is central to international humanitarian law. Yet are there distinctions among civilians that scholars of international law and international relations should consider? On the basis of US military documents and practices, we argue that in the recent conflicts in Iraq and Afghanistan, a hierarchy of 'civilianness' (Sutton) emerged. This hierarchy was structured along three observable axes of differentiation: personal security, compensation for harm, and credibility.
View Article and Find Full Text PDFInt J Law Psychiatry
September 2025
School of Law, University of Edinburgh, Old College, South Bridge, Edinburgh EH8 9YL, United Kingdom. Electronic address:
The Mental Health Act 1983 (MHA) authorizes the compulsory detention and treatment of people with mental disorders who are perceived to pose a risk to themselves or to others. Since its enactment, there have been concerns that the coercive powers of the Act have been disproportionately used for Black people with mental disorders. This disproportionate impact of the MHA on Black people is most clearly seen in the excessive use of Community Treatment Orders (CTOs).
View Article and Find Full Text PDFSmall
September 2025
South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials, South Chi
Self-assembled poly(2-dimethylaminoethyl methacrylate)-poly(2-(diisopropylamino)ethyl methacrylate) (PDMA-PDPA) diblock copolymer nanoparticles are widely employed in biological applications, driving the need for a robust and scalable production method. Although polymerization-induced self-assembly (PISA) enables efficient nanoparticle synthesis at high solids content, its research and application to PDMA-PDPA are limited, likely due to kinetic trapping. Leveraging our recently developed generic time-resolved small-angle X-ray scattering (TR-SAXS) approach for PISA in non-polar media, a reversible addition-fragmentation chain transfer-mediated PDMA-PDPA PISA process in polar solvent that produces spherical micelles is examined.
View Article and Find Full Text PDFChaos
September 2025
School of Science, Jiangxi University of Science and Technology, Ganzhou 341000, China.
Synaptic plasticity is of great significance for understanding the leaning and memory processes in different brain regions since it determines the synchronized firing activities of neurons. A volatility-switchable memristor-coupled heterogeneous neuron model is proposed to explore the effects of the synaptic plasticity on the synchronous dynamics of coupled neurons in different brain regions. With the increment of the non-volatility, the critical coupling strength of synchronization between two heterogeneous neurons decreases in a power-law relationship with the character parameter of the memristor.
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