14 research outputs found
Topics in electrodynamics of moving media Final report, 1 May 1965 - 1 May 1966
Electrodynamics of moving medi
Electrodynamics of moving media First semiannual report, 1 May - 1 Nov. 1965
Electrodynamics of moving media - Minkowski covariant formulation - Radiation due to oscillating dipole in vacuum - Field of moving charge in bounded region and Cerenkov radiatio
Evolutionary Breakpoints in the Gibbon Suggest Association between Cytosine Methylation and Karyotype Evolution
Gibbon species have accumulated an unusually high number of chromosomal changes since diverging from the common hominoid ancestor 15–18 million years ago. The cause of this increased rate of chromosomal rearrangements is not known, nor is it known if genome architecture has a role. To address this question, we analyzed sequences spanning 57 breaks of synteny between northern white-cheeked gibbons (Nomascus l. leucogenys) and humans. We find that the breakpoint regions are enriched in segmental duplications and repeats, with Alu elements being the most abundant. Alus located near the gibbon breakpoints (<150 bp) have a higher CpG content than other Alus. Bisulphite allelic sequencing reveals that these gibbon Alus have a lower average density of methylated cytosine that their human orthologues. The finding of higher CpG content and lower average CpG methylation suggests that the gibbon Alu elements are epigenetically distinct from their human orthologues. The association between undermethylation and chromosomal rearrangement in gibbons suggests a correlation between epigenetic state and structural genome variation in evolution
Genomic Hypomethylation in the Human Germline Associates with Selective Structural Mutability in the Human Genome
The hotspots of structural polymorphisms and structural mutability in the human genome remain to be explained mechanistically. We examine associations of structural mutability with germline DNA methylation and with non-allelic homologous recombination (NAHR) mediated by low-copy repeats (LCRs). Combined evidence from four human sperm methylome maps, human genome evolution, structural polymorphisms in the human population, and previous genomic and disease studies consistently points to a strong association of germline hypomethylation and genomic instability. Specifically, methylation deserts, the ∼1% fraction of the human genome with the lowest methylation in the germline, show a tenfold enrichment for structural rearrangements that occurred in the human genome since the branching of chimpanzee and are highly enriched for fast-evolving loci that regulate tissue-specific gene expression. Analysis of copy number variants (CNVs) from 400 human samples identified using a custom-designed array comparative genomic hybridization (aCGH) chip, combined with publicly available structural variation data, indicates that association of structural mutability with germline hypomethylation is comparable in magnitude to the association of structural mutability with LCR–mediated NAHR. Moreover, rare CNVs occurring in the genomes of individuals diagnosed with schizophrenia, bipolar disorder, and developmental delay and de novo CNVs occurring in those diagnosed with autism are significantly more concentrated within hypomethylated regions. These findings suggest a new connection between the epigenome, selective mutability, evolution, and human disease
Derivation of Aerospace Antenna Coupling - Factor Interference Prediction Techniques
http://deepblue.lib.umich.edu/bitstream/2027.42/21244/2/rl2119.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/21244/1/rl2119.0001.001.tx
Derivation of aerospace antenna coupling-factor interference prediction techniques : interim report
http://deepblue.lib.umich.edu/bitstream/2027.42/6410/5/bad0635.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/6410/4/bad0635.0001.001.tx