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The physics of shear waves traveling through matter carries fundamental insights into its structure, for instance, quantifying stiffness for disease characterization. However, the origin of shear wave attenuation in tissue is currently not properly understood. Attenuation is caused by two phenomena: absorption due to energy dissipation and scattering on structures such as vessels fundamentally tied to the material’s microstructure. Here, we present a scattering theory in conjunction with magnetic resonance imaging, which enables the unraveling of a material’s innate constitutive and scattering characteristics. By overcoming a three-order-of-magnitude scale difference between wavelength and average intervessel distance, we provide noninvasively a macroscopic measure of vascular architecture. The validity of the theory is demonstrated through simulations, phantoms, in vivo mice, and human experiments and compared against histology as gold standard. Our approach expands the field of imaging by using the dispersion properties of shear waves as macroscopic observable proxies for deciphering the underlying ultrastructures. 

Honduras cuenta con 349,510 hectáreas cultivadas con café Coffea arabica, que son en su mayoría cultivos tradicionales (café sombra y café sol), y en menor escala cultivos con sistema Dosel Abierto Integrado (DAI). El sistema de café DAI consiste en plantaciones de café rodeadas por bosque en una proporción ≥ 1:1, lo que permite la preservación y la restauración de ecosistemas nativos. El objetivo de nuestra investigación fue evaluar el sistema DAI en cultivos de café como una alternativa de conservación para las aves migratorias neártico-neotropicales y aves residentes. Evaluamos características ecológicas, como la riqueza y abundancia de especies, entre los meses de noviembre de 2018 a abril de 2019. Establecimos 75 puntos de conteo de radio fijo en una zona cafetalera del departamento de Yoro, Honduras. Estadísticamente no registramos diferencias significativas en la riqueza de aves migratorias entre los sistemas de bosque, café DAI y cultivos de café tradicionales. Sin embargo, la riqueza de especies dependientes de bosque fue mayor en los sistema bosque y cultivos de café DAI que en cultivos tradicionales. Además, algunas especies dependientes de bosque, como Myioborus miniatus y Mionectes oleagineus, fueron más abundantes (P < 0.05) en bosque y cultivos de café DAI que en cultivos de café tradicionales. Nuestros resultados se suman a los reportados en Costa Rica, en donde se introdujo este agroecosistema de cultivo de café, en los que se indica que el café DAI puede ser una alternativa para la conservación de aves migratorias y residentes, en particular para especies dependientes de bosque. 

Abstract The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs)¹, sources of high-frequency gravitational waves (GWs)²and likely production sites for heavy-element nucleosynthesis by means of rapid neutron capture (ther-process)³. Here we present observations of the exceptionally bright GRB 230307A. We show that GRB 230307A belongs to the class of long-duration GRBs associated with compact object mergers^4–6and contains a kilonova similar to AT2017gfo, associated with the GW merger GW170817 (refs. ^7–12). We obtained James Webb Space Telescope (JWST) mid-infrared imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns, which we interpret as tellurium (atomic massA = 130) and a very red source, emitting most of its light in the mid-infrared owing to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can creater-process elements across a broad atomic mass range and play a central role in heavy-element nucleosynthesis across the Universe.