Theory indicates that competing species coexist in a community when intraspecific competition is stronger than interspecific competition. When body size determines the outcome of competitive interactions between individuals, coexistence depends also on how resource use and the ability to compete for these resources change with body size. Testing coexistence theory in size-structured communities, therefore, requires disentangling the effects of size-dependent competitive abilities and niche shifts. Here, we tested the hypothesis that the evolution of species- and size-dependent competitive asymmetries increased the likelihood of coexistence between interacting species. We experimentally estimated the effects of size-dependent competitive interactions on somatic growth rates of two interacting fish species, Trinidadian guppies Poecilia reticulata and killifish Rivulus hartii. We controlled for the effects of size-dependent changes in the niche at two competitive settings representing the early (allopatric) and late (sympatric) evolutionary stages of a killifish-guppy community. We fitted the growth data to a model that incorporates species- and size-dependent competitive asymmetries to test whether changes in the competitive interactions across sizes increased the likelihood of species coexistence from allopatry to sympatry. We found that guppies are competitively superior to killifish but were less so in sympatric populations. The decrease in the effects of interspecific competition on the fitness of killifish and increase in the interspecific effect on guppies' fitness increased the likelihood that sympatric guppies and killifish will coexist. However, while the competitive asymmetries between the species changed consistently between allopatry and sympatry between drainages, the magnitude of the size-dependent competitive asymmetries varied between drainages. These results demonstrate the importance of integrating evolution and trait-based interactions into the research on how species coexist.
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http://dx.doi.org/10.1111/1365-2656.13577 | DOI Listing |
In this work, electrical and optical performances for 250 nm AlGaN-based flip-chip deep ultraviolet light emitting diodes (DUV LEDs) with different chip sizes are studied. Reduced chip size helps increase the light extraction efficiency (LEE) with the cost of increased surface nonradiative recombination. Nevertheless, a thin p-AlGaN layer of 10 nm can manage current distribution while suppressing surface recombination and reducing light absorption simultaneously, which results in the increased optical power density.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2024
Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Nanoparticles (NPs) continue to be developed as labels for bioanalysis and imaging due to their small size and, in many cases, emergent properties such as photoluminescence (PL) and superparamagnetism. Some applications stand to benefit from amplification of the advantageous properties of a NP, but this amplification is not a simple matter of scaling for size-dependent properties. One promising approach to amplification is, therefore, to assemble many copies of a NP into a larger but still nanoscale and colloidal entity.
View Article and Find Full Text PDFNanoscale
October 2024
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing 210093, China.
The investigation of nanocluster behaviors at elevated temperatures is important because it encompasses temperature-dependent structural evolution and size-dependent melting points. Size-selected Au, Au, Au, and Au clusters were generated using a gas-phase condensation cluster beam source equipped with a lateral time-of-flight mass selector. Comprehensive heating characterization was conducted, revealing the structural evolution and size-dependent melting point depression of Au clusters at atomic resolution aberration-corrected scanning transmission electron microscopy (AC-STEM).
View Article and Find Full Text PDFJ Phys Chem Lett
September 2024
Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China.
Great efforts have been devoted to understanding the stability and reactivity of silver clusters, which usually depend on geometric structures, electronic configuration, and cluster size. Despite the fact that the jellium model and Wulff construction rule have successfully rationalized the stable clusters with "magic number" behavior, some experiments imply that silver clusters with 48 valence electrons also possess puzzling enhanced stability. In this work, using a recently developed deep learning technology, i.
View Article and Find Full Text PDFAm J Bot
August 2024
Department of Biology, Terrestrial Ecology Unit, Ghent University, Karel Lodewijk Ledeganckstraat 35, BE-9000 Ghent, Belgium.
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