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Introgression between species has the potential to shape evolutionary trajectories in important ways, but uncovering complex introgression dynamics has only recently been made possible by advances in genomics. Warblers of the avian family Parulidae exemplify rapid diversification and sexual trait divergence, and we endeavored to study historical introgression in the family. We sequenced multiple genomes of nearly every species, constructed a phylogeny for the family, and investigated gene flow across the genome and at genes known for controlling feather color. We found that DNA haplotypes including the geneBCO2, which encodes an enzyme that degrades yellow carotenoids, have spread among genera multiple times—fromVermivoratoGeothlypisand fromLeiothlypisto multipleCardellinaandSetophagaspecies. Patterns of inheritance in the latter case point to introgression that occurred 0.5 to 2 million years ago, and the shared haplotype among recipient species is less than 100 nucleotides long. Separately, we found evidence of introgression from redCardellinaspecies to both of the two redMyioborusspecies atBDH1Land from one redMyioborusspecies to the other atCYP2J19; both are key genes in the pathway that converts yellow carotenoids to red ketocarotenoids. Our results show that introgression is a common mechanism for the evolution of colorful plumage in parulid warblers and hint at complex histories of gene flow behind some of the Western Hemisphere’s most colorful birds. 

Hybrid materials combining the optoelectronic absorption and tunability of quantum dots (QDs) with the high surface area, chemical functionality, and porosity of metal-organic frameworks (MOFs) are emerging as systems with unique optoelectronic properties relevant to applications in catalysis, sensing, and energy conversion and storage. A key component of the electronic interaction between QDs and MOFs is the transfer of charge between the two materials. This review examines the mechanisms driving charge transfer at the QD/MOF interfaces and the effects that both physical and chemical composition have on this process. We provide an overview of the key experimental approaches, including spectroscopic and electrochemical techniques, which have been used for probing charge transfer dynamics in this hybrid system. Challenges in controlling interfacial structure, distinguishing between charge and energy transfer, and optimizing stability are also discussed. This review highlights recent work on the preparation and characterization of QD/MOF hybrid materials, as well as fundamental studies advancing the understanding of charge transfer processes that occur in these systems. 

Tellurium oxide-based glasses were made by the melt quenching technique. Appropriate quantities of the chemicals were weighed, mixed/ ground, and then melted above the melting point for an hour. Samarium and Silver compound were added to the starting chemicals. The melt was poured into an aluminum mold to get different shapes and sizes. The spectroscopic characterization of the samples was done by using different laser excitation sources. Silver metallic particles were induced by heat treating the glass above its glass transition temperature. Absorption and emission measurements revealed enhanced characteristics.