Application of special-purpose digital computers to rotorcraft real-time simulation

The use of an array processor as a computational element in rotorcraft real-time simulation is studied. A multilooping scheme was considered in which the rotor would loop over its calculations a number of time while the remainder of the model cycled once on a host computer. To prove that such a method would realistically simulate rotorcraft, a FORTRAN program was constructed to emulate a typical host-array processor computing configuration. The multilooping of an expanded rotor model, which included appropriate kinematic equations, resulted in an accurate and stable simulation

Rogue decoherence in the formation of a macroscopic atom-molecule superposition

We theoretically examine two-color photoassociation of a Bose-Einstein condensate, focusing on the role of rogue decoherence in the formation of macroscopic atom-molecule superpositions. Rogue dissociation occurs when two zero-momentum condensate atoms are photoassociated into a molecule, which then dissociates into a pair of atoms of equal-and-opposite momentum, instead of dissociating back to the zero-momentum condensate. As a source of decoherence that may damp quantum correlations in the condensates, rogue dissociation is an obstacle to the formation of a macroscopic atom-molecule superposition. We study rogue decoherence in a setup which, without decoherence, yields a macroscopic atom-molecule superposition, and find that the most favorable conditions for said superposition are a density ~ 1e12 atoms per cc and temperature ~ 1e-10.Comment: 10 pages, 4 figures, 46+ references; submitted to PR

Chemical Probes for Protein α-N-Terminal Methylation

While protein α-N-terminal methylation has been known for nearly four decades since it was first uncovered on bacteria ribosomal proteins L33, the function of this modification is still not entirely understood. Recent discoveries have demonstrated α-N-terminal methylation is essential to stabilize the interactions between regulator of chromosome condensation 1 (RCC1) and chromatin during mitosis, to localize and enhance the interaction of centromere proteins (CENPs) with chromatin, and to facilitate the recruitment of DNA damage-binding protein 2 (DDB2) to DNA damage foci. Identification of N-terminal methyltransferase 1 (NTMT1) unveiled the eukaryotic methylation writer for protein α-N-termini. In addition, NTMT2 that shares over 50% sequence similarity, has been identified as another mammalian protein α-N-terminal methylation writer. Knockdown of NTMT1 results in mitotic defects and sensitizes chemotherapeutic agents in breast cancer cell lines, while NTMT1 knockout mice showed premature aging. Additionally, NTMT1 has been shown to be overexpressed in a colorectal and melanoma tumor tissues, and in lung and liver cancer cell lines. Given the vast array of clinical relevance, chemical probes and inhibitors for NTMT1 are vital to elucidate information about the function and downstream process of protein α-N-terminal methylation. Therefore, 47 peptidomimetic compounds have been synthesized that target NTMT1. These peptide-based compounds range from three to six amino acids in length and the top 5 compounds have 3- to 300- fold selectivity for NTMT1 compared to other methyltransferases. An inhibition mechanism study has also been performed to verify the inhibitors are targeting the NTMT1 peptide binding site. Seven compounds have an IC50 of less than 5 µM and our top inhibitor, BM-47, has an IC50 of 0.32 µM ± 0.06 for NTMT1. To further elucidate information about the NTMTs and their downstream effects, we utilized photoaffinity probes to target these enzymes. Our 6 photoaffinity probes exhibited in a dose- and time-dependent manner. Probe labeling has been shown to be driven by recognition and selectively and competitively label the NTMT writers in a complex cellular mixture. Our results also provided the first indication of substrate preferences among NTMT1/2. Methylated photoaffinity probes were also synthesized to identify novel proteins that recognize a methylated N-terminus and shed light on the function of α-N-terminal methylation

Teaching the Philosophy of Education

In \u27Problems in Teaching Philosophy of Education\u27, Australian Journal of Teacher Education, Vol 11, No 1, 1986, M A B Degenhardt pinpoints the \u27difficulty\u27 in teaching this subject when he outlines an imaginary lecture on \u27Discipline and Punishment\u27. At the end of this lecture, he says, the students \u27will have learned that there is a general agreement on what punishment is, that there are three main theories of punishment ... , that all have strong points \u27 and that much more will need to be done towards the development of a satisfactory theory of punishment in education\u27 (p.31). He concludes that the students leave wondering what all this tells them about what to do if children flick paper pellets during next week\u27s poetry lesson

Rate limit for photoassociation of a Bose-Einstein condensate

We simulate numerically the photodissociation of molecules into noncondensate atom pairs that accompanies photoassociation of an atomic Bose-Einstein condensate into a molecular condensate. Such rogue photodissociation sets a limit on the achievable rate of photoassociation. Given the atom density \rho and mass m, the limit is approximately 6\hbar\rho^{2/3}/m. At low temperatures this is a more stringent restriction than the unitary limit of scattering theory.Comment: 5 pgs, 18 refs., 3 figs., submitted to Phys. Rev. Let