V-Mail (Victory Mail) Letter, W. A. Tyson in Tupelo, Mississippi to Major Rollin S. Armstrong, in North Africa, October 30, 1943

This typed V-Mail (Victory Mail) letter, dated October 30, 1943, is written by W. A. Tyson, the pastor of the First Methodist Church in Tupelo, Mississippi, to Major Rollin S. Armstrong from where he is stationed in North Africa. The letter describes Tyson\u27s recent visit with Armstrong\u27s newborn son and encourages the new father.https://scholarsjunction.msstate.edu/mss-armstrong-papers/1053/thumbnail.jp

CRISPR-mediated phage resistance and the ghost of coevolution past

The past is never dead. It's not even pastWilliam Faulkner (1951

Spin-Coupled Local Distortions in Multiferroic Hexagonal HoMnO3

Local structural measurements have been performed on hexagonal HoMnO3 in order to ascertain the specific changes in bond distances which accompany magnetic ordering transitions. The transition from paramagnetic to the antiferromagetic (noncollinear) phase near ~70 K is dominated by changes in the a-b plane Mn-Mn bond distances. The spin rotation transition near ~40 K involves both Mn-Mn and nearest neighbor Ho-Mn interactions while the low temperature transition below 10 K involves all interactions, Mn-Mn, Ho-Mn (nearest and next nearest) and Ho-Ho correlations. These changes in bond distances reveal strong spin-lattice coupling. The similarity in magnitude of the change in J(Mn-Mn) and J(Ho-Mn) enhances the system frustration. The structural changes are interpreted in terms of a model of competing spin order and local structural distortions. Density functional calculations are used to estimate the energies associated with ionic displacements. The calculations also reveal asymmetric polarization of the charge density of Ho, O3 and O4 sites along the z-axis in the ferroelectric phase. This polarization facilitates coupling between Ho atoms on neighboring planes normal to the z-axis.Comment: 8 figure

Classification of image distortions in terms of Petrov types

An observer surrounded by sufficiently small spherical light sources at a fixed distance will see a pattern of elliptical images distributed over the sky, owing to the distortion effect (shearing effect) of the spacetime geometry upon light bundles. In lowest non-trivial order with respect to the distance, this pattern is completely determined by the conformal curvature tensor (Weyl tensor) at the observation event. In this paper we derive formulas that allow to calculate these distortion patterns in terms of the Newman-Penrose formalism. Then we represent the distortion patterns graphically for all Petrov types, and we discuss their dependence on the velocity of the observer.Comment: 22 pages, 8 eps-figures; revised version, parts of Introduction and Conclusions rewritte

Response of selected plant and insect species to simulated solid rocket exhaust mixtures and to exhaust components from solid rocket fuels

The effects of solid rocket fuel (SRF) exhaust on selected plant and and insect species in the Merritt Island, Florida area was investigated in order to determine if the exhaust clouds generated by shuttle launches would adversely affect the native, plants of the Merritt Island Wildlife Refuge, the citrus production, or the beekeeping industry of the island. Conditions were simulated in greenhouse exposure chambers and field chambers constructed to model the ideal continuous stirred tank reactor. A plant exposure system was developed for dispensing and monitoring the two major chemicals in SRF exhaust, HCl and Al203, and for dispensing and monitoring SRF exhaust (controlled fuel burns). Plants native to Merritt Island, Florida were grown and used as test species. Dose-response relationships were determined for short term exposure of selected plant species to HCl, Al203, and mixtures of the two to SRF exhaust

Methods for comparative evaluation of propulsion system designs for supersonic aircraft

The propulsion system comparative evaluation study was conducted to define a rapid, approximate method for evaluating the effects of propulsion system changes for an advanced supersonic cruise airplane, and to verify the approximate method by comparing its mission performance results with those from a more detailed analysis. A table look up computer program was developed to determine nacelle drag increments for a range of parametric nacelle shapes and sizes. Aircraft sensitivities to propulsion parameters were defined. Nacelle shapes, installed weights, and installed performance was determined for four study engines selected from the NASA supersonic cruise aircraft research (SCAR) engine studies program. Both rapid evaluation method (using sensitivities) and traditional preliminary design methods were then used to assess the four engines. The method was found to compare well with the more detailed analyses

The Size Distribution of Trans-Neptunian Bodies

[Condensed] We search 0.02 deg^2 for trans-Neptunian objects (TNOs) with m<=29.2 (diameter ~15 km) using the ACS on HST. Three new objects are discovered, roughly 25 times fewer than expected from extrapolation of the differential sky density Sigma(m) of brighter objects. The ACS and other recent TNO surveys show departures from a power law size distribution. Division of the TNO sample into ``classical Kuiper belt'' (CKB) and ``Excited'' samples reveals that Sigma(m) differs for the two populations at 96% confidence. A double power law adequately fits all data. Implications include: The total mass of the CKB is ~0.010 M_Earth, only a few times Pluto's mass, and is predominately in the form of ~100 km bodies. The mass of Excited objects is perhaps a few times larger. The Excited class has a shallower bright-end size distribution; the largest objects, including Pluto, comprise tens of percent of the total mass whereas the largest CKBOs are only ~2% of its mass. The predicted mass of the largest Excited body is close to the Pluto mass; the largest CKBO is ~60 times less massive. The deficit of small TNOs occurs for sizes subject to disruption by present-day collisions, suggesting extensive depletion by collisions. Both accretion and erosion appearing to have proceeded to more advanced stages in the Excited class than the CKB. The absence of distant TNOs implies that any distant (60 AU) population must have less than the CKB mass in the form of objects 40 km or larger. The CKB population is sparser than theoretical estimates of the required precursor population for short period comets, but the Excited population could be a viable precursor population.Comment: Revised version accepted to the Astronomical Journal. Numerical results are very slightly revised. Implications for the origins of short-period comets are substantially revised, and tedious material on statistical tests has been collected into a new Appendi

Operator-Schmidt decompositions and the Fourier transform, with applications to the operator-Schmidt numbers of unitaries

The operator-Schmidt decomposition is useful in quantum information theory for quantifying the nonlocality of bipartite unitary operations. We construct a family of unitary operators on C^n tensor C^n whose operator-Schmidt decompositions are computed using the discrete Fourier transform. As a corollary, we produce unitaries on C^3 tensor C^3 with operator-Schmidt number S for every S in {1,...,9}. This corollary was unexpected, since it contradicted reasonable conjectures of Nielsen et al [Phys. Rev. A 67 (2003) 052301] based on intuition from a striking result in the two-qubit case. By the results of Dur, Vidal, and Cirac [Phys. Rev. Lett. 89 (2002) 057901 quant-ph/0112124], who also considered the two-qubit case, our result implies that there are nine equivalence classes of unitaries on C^3 tensor C^3 which are probabilistically interconvertible by (stochastic) local operations and classical communication. As another corollary, a prescription is produced for constructing maximally-entangled operators from biunimodular functions. Reversing tact, we state a generalized operator-Schmidt decomposition of the quantum Fourier transform considered as an operator C^M_1 tensor C^M_2 --> C^N_1 tensor C^N_2, with M_1 x M_2 = N_1 x N_2. This decomposition shows (by Nielsen's bound) that the communication cost of the QFT remains maximal when a net transfer of qudits is permitted. In an appendix, a canonical procedure is given for removing basis-dependence for results and proofs depending on the "magic basis" introduced in [S. Hill and W. Wootters, "Entanglement of a pair of quantum bits," Phys Rev. Lett 78 (1997) 5022-5025, quant-ph/9703041 (and quant-ph/9709029)].Comment: More formal version of my talk at the Simons Conference on Quantum and Reversible Computation at Stony Brook May 31, 2003. The talk slides and audio are available at http://www.physics.sunysb.edu/itp/conf/simons-qcomputation.html. Fixed typos and minor cosmetic

Direct Detection and Sequencing of Damaged DNA Bases

Products of various forms of DNA damage have been implicated in a variety of important biological processes, such as aging, neurodegenerative diseases, and cancer. Therefore, there exists great interest to develop methods for interrogating damaged DNA in the context of sequencing. Here, we demonstrate that single-molecule, real-time (SMRT®) DNA sequencing can directly detect damaged DNA bases in the DNA template - as a by-product of the sequencing method - through an analysis of the DNA polymerase kinetics that are altered by the presence of a modified base. We demonstrate the sequencing of several DNA templates containing products of DNA damage, including 8-oxoguanine, 8-oxoadenine, O6-methylguanine, 1-methyladenine, O4-methylthymine, 5-hydroxycytosine, 5-hydroxyuracil, 5-hydroxymethyluracil, or thymine dimers, and show that these base modifications can be readily detected with single-modification resolution and DNA strand specificity. We characterize the distinct kinetic signatures generated by these DNA base modifications