Final design and fabrication of an active control system for flutter suppression on a supercritical aeroelastic research wing

The final design and hardware fabrication was completed for an active control system capable of the required flutter suppression, compatible with and ready for installation in the NASA aeroelastic research wing number 1 (ARW-1) on Firebee II drone flight test vehicle. The flutter suppression system uses vertical acceleration at win buttock line 1.930 (76), with fuselage vertical and roll accelerations subtracted out, to drive wing outboard aileron control surfaces through appropriate symmetric and antisymmetric shaping filters. The goal of providing an increase of 20 percent above the unaugmented vehicle flutter velocity but below the maximum operating condition at Mach 0.98 is exceeded by the final flutter suppression system. Results indicate that the flutter suppression system mechanical and electronic components are ready for installation on the DAST ARW-1 wing and BQM-34E/F drone fuselage

Colloidal Gold - A Powerful Tool in Scanning Electron Microscope Immunocytochemistry: An Overview of Bioapplications

Colloidal gold may be conjugated to a wide variety of macromolecules, provides a versatile system for immunocytochemical studies by various types of microscopy (light and fluorescent microscopy, scanning (SEM) and transmission (TEM) electron microscopy), and is significantly contributing to the development of SEM immunocytochemistry as a routine analytical procedure. A comprehensive overview has been compiled of the literature on SEM bioapplications of colloidal gold. This is illustrated through a selected series of studies focussing on a) cell surface receptor-ligand interactions; b) expression of cell surface lectin-binding sites; c) surface distribution of extracellular matrix components; and d) visualization of gold-labelled cytoskeletal elements with emphasis on the use of backscattered electron imaging as a powerful analytical adjunct in the development of SEM immunocytochemistry

Agricultural and Natural Resources Awareness Programming: Barriers and Benefits as Perceived by County Extension Agents

The study described here assessed Extension agents\u27 perceived barriers and benefits concerning a new Florida agricultural and natural resources awareness initiative and Web site. A total of 186 agents responded to a statewide Web-based needs assessment, for an overall response rate of 58%. Results highlighted several barriers to communicating about agriculture and natural resources, including (a) a lack of interest, knowledge, and awareness among the general public, government, clientele, and media, (b) a lack of agent access to resources/contacts, and (c) inconsistent/ineffective message delivery methods. Concerning the Web site, most respondents wanted information to be presented via fact sheets, economic facts, and downloadable brochures

Experimental Implementation of Logical Bell State Encoding

Liquid phase NMR is a general purpose test-bed for developing methods of coherent control relevant to quantum information processing. Here we extend these studies to the coherent control of logical qubits and in particular to the unitary gates necessary to create entanglement between logical qubits. We report an experimental implementation of a conditional logical gate between two logical qubits that are each in decoherence free subspaces that protect the quantum information from fully correlated dephasing.Comment: 9 Pages, 5 Figure

De novo DNA demethylation and non-coding transcription define active intergenic regulatory elements

Deep sequencing of mammalian DNA methylomes has uncovered a previously unpredicted number of discrete hypomethylated regions in intergenic space (iHMRs). Here, we combined whole genome bisulfite sequencing data with extensive gene-expression and chromatin-state data to define functional classes of iHMRs, and to reconstruct the dynamics of their establishment in a developmental setting. Comparing HMR profiles in embryonic stem and primary blood cells, we show that iHMRs mark an exclusive subset of active DNase hypersensitive sites (DHS), and that both developmentally constitutive and cell-type specific iHMRs display chromatin states typical of distinct regulatory elements. We also observe that iHMR changes are more predictive of nearby gene activity than the promoter HMR itself, and that expression of non-coding RNAs within the iHMR accompanies full activation and complete demethylation of mature B cell enhancers. Conserved sequence features corresponding to iHMR transcript start sites, including a discernable TATAA motif, suggest a conserved, functional role for transcription in these regions. Similarly, we explored both primate-specific and human-population variation at iHMRs, finding that while enhancer iHMRs are more variable in sequence and methylation status than any other functional class, conservation of the TATA box is highly predictive of iHMR maintenance, reflecting the impact of sequence plasticity and transcriptional signals on iHMR establishment. Overall, our analysis allowed us to construct a 3-step timeline in which 1) intergenic DHS are pre-established in the stem cell, 2) partial demethylation of blood specific intergenic DHSs occurs in blood progenitors, and 3) complete iHMR formation and transcription coincide with enhancer activation in lymphoid-specified cells

Genomic landscape of human allele-specific DNA methylation

DNA methylation mediates imprinted gene expression by passing an epigenomic state across generations and differentially marking specific regulatory regions on maternal and paternal alleles. Imprinting has been tied to the evolution of the placenta in mammals and defects of imprinting have been associated with human diseases. Although recent advances in genome sequencing have revolutionized the study of DNA methylation, existing methylome data remain largely untapped in the study of imprinting. We present a statistical model to describe allele-specific methylation (ASM) in data from high-throughput short-read bisulfite sequencing. Simulation results indicate technical specifications of existing methylome data, such as read length and coverage, are sufficient for fullgenome ASM profiling based on our model. We used our model to analyze methylomes for a diverse set of human cell types, including cultured and uncultured differentiated cells, embryonic stem cells and induced pluripotent stem cells. Regions of ASM identified most consistently across methylomes are tightly connected with known imprinted genes and precisely delineate the boundaries of several known imprinting control regions. Predicted regions of ASM common to multiple cell types frequently mark noncoding RNA promoters and represent promising starting points for targeted validation. More generally, our model provides the analytical complement to cutting-edge experimental technologies for surveying ASM in specific cell types and across species

Normal Fermi Liquid Behavior of Quasiholes in the Spin-Polaron Model for Copper Oxides

Based on the t-J model and the self-consistent Born approximation, the damping of quasiparticle hole states near the Fermi surface is calculated in a low doping regime. Renormalization of spin-wave excitations due to hole doping is taken into account. The damping is shown to be described by a familiar form $\text{Im}\Sigma({\bf k}^{\prime},\epsilon)\propto (\epsilon^{2}/ \epsilon_{F})\ln(\epsilon/ \epsilon_{F})$ characteristic of the 2-dimensional Fermi liquid, in contrast with the earlier statement reported by Li and Gong [Phys. Rev. B {\bf 51}, 6343 (1995)] on the marginal Fermi liquid behavior of quasiholes

Recovering the Inflationary Potential

A procedure is developed for the recovery of the inflationary potential over the interval that affects astrophysical scales (\approx 1\Mpc - 10^4\Mpc). The amplitudes of the scalar and tensor metric perturbations and their power-spectrum indices, which can in principle be inferred from large-angle CBR anisotropy experiments and other cosmological data, determine the value of the inflationary potential and its first two derivatives. From these, the inflationary potential can be reconstructed in a Taylor series and the consistency of the inflationary hypothesis tested. A number of examples are presented, and the effect of observational uncertainties is discussed.Comment: 13 pages LaTeX, 6 Figs. available on request, FNAL-Pub-93/182-