Phylogenetic tree of Litopterna and Perissodactyla indicates a complex early history of hoofed mammals [X26817] Final matrix for "Phylogenetic tree of Litopterna and Perissodactyla indicates a complex early history of hoofed mammals"

AbstractThe faith that “comparative analysis of the behaviour of modern primates, in conjunction with an accurate phylogenetic tree of relatedness, has the power to chart the early history of human cognitive evolution” (Byrne 2000 p. 543) runs afoul of the fact that no other primate besides humans is capable of vocal production learning. This basic enabling adaptation for articulate speech bears crucially on the reconstruction of language origins.

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Phylogenetic tree of Litopterna and Perissodactyla indicates a complex early history of hoofed mammals

Scientific Reports ◽

10.1038/s41598-020-70287-5 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Nicolás R. Chimento ◽

Federico L. Agnolin

Keyword(s):

Phylogenetic Tree ◽

Early History ◽

History Of

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Some early history of replica techniques for electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130018 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1076-1077

Author(s):

Robert M. Fisher

Keyword(s):

Thin Film ◽

Electron Microscopy ◽

Optical Microscope ◽

Early History ◽

Bulk Materials ◽

Thin Sections ◽

Transmission Electron ◽

Reflected Light ◽

History Of ◽

Electron Microscopes

By 1940, a half dozen or so commercial or home-built transmission electron microscopes were in use for studies of the ultrastructure of matter. These operated at 30-60 kV and most pioneering microscopists were preoccupied with their search for electron transparent substrates to support dispersions of particulates or bacteria for TEM examination and did not contemplate studies of bulk materials. Metallurgist H. Mahl and other physical scientists, accustomed to examining etched, deformed or machined specimens by reflected light in the optical microscope, were also highly motivated to capitalize on the superior resolution of the electron microscope. Mahl originated several methods of preparing thin oxide or lacquer impressions of surfaces that were transparent in his 50 kV TEM. The utility of replication was recognized immediately and many variations on the theme, including two-step negative-positive replicas, soon appeared. Intense development of replica techniques slowed after 1955 but important advances still occur. The availability of 100 kV instruments, advent of thin film methods for metals and ceramics and microtoming of thin sections for biological specimens largely eliminated any need to resort to replicas.

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