7 research outputs found
Seismic Stabilization of Historic Adobe Structures: Final Report of the Getty Seismic Adobe Project
Provides the final report of GSAP activities, and the first publication to provide an overview of the results of scale-model laboratory research along with field data from a survey of damage to historic adobe buildings after an actual earthquake
Preparation of fused clay radiation sources.
"Brookhaven National Laboratory, Associated Universities, Inc. under contract with the United States Atomic Energy Commission"--Cover."June 1955."Includes bibliographical references.Mode of access: Internet
Preparation of spherical clay particles containing radioactive ions /
"This report is a revision of BNL-1105.""November 1952."Includes bibliographical references (p. xx)Mode of access: Internet
\u3ci\u3eDrosophila\u3c/i\u3e Muller F Elements Maintain a Distinct Set of Genomic Properties Over 40 Million Years of Evolution
The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25β50%) than euchromatic reference regions (3β11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11β27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4β3.6 vs. 8.4β8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu