The radiation resistance-repair genes in Deinococcus radiodurans (DR) and E-coli were analyzed in terms of the A, T, C, G nucleotide fluctuations. The studied genes were Rec-A, Rec-Q, and the unique DR PprA gene. In an ATCG sequence, each base was assigned a number equal to its atomic number. The resulting numerical sequence was the basis of the statistical analysis. Fractal analysis using the Higuchi method gave a fractal dimension increase of the Deinococcus radiodurans genes as compared to E-coli, which is comparable to the enhancement observed in the human HAR1 region (HAR1F gene) over that of the chimpanzee. Near neighbor fluctuation was also studied via the Black-Scholes model where the increment sequence was treated as a random walk series. The Deinococcus radiodurans radiation gene standard deviations were consistently higher than that of the E-coli deviations, and agree with the fractal analysis results. The sequence stacking interaction was studied using the published nucleotide-pair melting free energy values and Deinococcus radiodurans radiation genes were shown to possess larger negative free energies. The high sensitivity of the fractal dimension as a biomarker was tested with correlation analysis of the gamma ray dose versus fractal dimension, and the R square values were found to be above 0.9 (N=5). When compared with other nucleotide sequences such as the rRNA sequences, HAR1 and its chimpanzee counterpart, the higher fluctuation (correlated randomness) and larger negative free energy of a DR radiation gene suggested that a radiation resistance-repair sequence exhibited higher complexity. As the HAR1 nucleotide sequence complexity and its transcription activity of co-expressing cortex protein reelin supported a positive selection event in humans, a similar inference of positive selection of coding genes could be drawn for Deinococcus radiodurans when compared to E-coli. The origin of such a positive selection would be consistent with that of a Martian environment.
Complex patterns with 75-125 nm feature sizes exposed with x-ray lithography are shown. Lithographic results for 75-125 nm lines with varying pitch are compared to simulations of image formation and resist dissolution, showing good qualitative agreement. Exposure dose latitude, nested-to-isolated print bias, image shortening, linewidth change with gap, and linearity of printed linewidth versus mask linewidth are quantified for 11-22.5 m gaps. Critical dimension control error budgets for resist linewidth uniformity are determined for logic patterns at 75 and 100 nm ground rules. Image shortening is quantified for 75-125 nm ground rule static random access memory-like patterns, indicating hammerheads added to line ends reduce shortening to acceptable levels for у100 nm ground rules at р17.5 m gaps. With tight gap control and tight mask linewidth control, 100 nm ground rule complex patterns can be printed with good latitude using x-ray lithography.
An experiment has been performed to examine the time variation of the position and visibility of a transient interference pattern from a single-mode, passively Q-switched ruby laser. A blue shift in the emission frequency as a function of time is observed. The power-dependent rate of frequency shift is 3.4 MHz/nsec·MW. This frequency shift is consistent with the results from previous experiments with a normally spiking ruby laser. A model is proposed which correlates the change in optical length of the ruby to changes in population inversion during emission. Predictions based on the model are in agreement with experimental results and with previous work.
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