Digital flight control and landing system for the CH-46C helicopter Final report

Systems analysis of flight control and guidance of CH-46C helicopte

Effects of Vacancies on Properties of Relaxor Ferroelectrics: a First-Principles Study

A first-principles-based model is developed to investigate the influence of lead vacancies on the properties of relaxor ferroelectric Pb(Sc1/2Nb1/2)O3 (PSN). Lead vacancies generate large, inhomogeneous, electric fields that reduce barriers between energy minima for different polarization directions. This naturally explains why relaxors with significant lead vacancy concentrations have broadened dielectric peaks at lower temperatures, and why lead vacancies smear properties in the neighborhood of the ferroelectric transition in PSN. We also reconsider the conventional wisdom that lead vacancies reduce the magnitude of dielectric response.Comment: 11 pages, 1 figur

The Sleep Or Mood Novel Adjunctive therapy (SOMNA) trial: a study protocol for a randomised controlled trial evaluating an internet-delivered cognitive behavioural therapy program for insomnia on outcomes of standard treatment for depression in men

BACKGROUND: Insomnia is a significant risk factor for depression onset, can result in more disabling depressive illness, and is a common residual symptom following treatment cessation that can increase the risk of relapse. Internet-based cognitive behavioural therapy for insomnia has demonstrated efficacy and acceptability to men who are less likely than women to seek help in standard care. We aim to evaluate whether internet delivered cognitive behavioural therapy for insomnia as an adjunct to a standard depression therapeutic plan can lead to improved mood outcomes.METHODS/DESIGN: Male participants aged 50 years or more, meeting Diagnostic and Statistical Manual of Mental Disorders criteria for current Major Depressive Episode and/or Dysthymia and self-reported insomnia symptoms, will be screened to participate in a single-centre double-blind randomised controlled trial with two parallel groups involving adjunctive internet-delivered cognitive behavioural therapy for insomnia and an internet-based control program. The trial will consist of a nine-week insomnia intervention period with a six-month follow-up period. During the insomnia intervention period participants will have their depression management coordinated by a psychiatrist using standard guideline-based depression treatments. The study will be conducted in urban New South Wales, Australia, where 80 participants from primary and secondary care and direct from the local community will be recruited. The primary outcome is change in the severity of depressive symptoms from baseline to week 12. DISCUSSION: This study will provide evidence on whether a widely accessible, evidence-based, internet-delivered cognitive behavioural therapy for insomnia intervention can lead to greater improvements than standard treatment for depression alone, in a group who traditionally do not readily access psychotherapy. The study is designed to establish effect size, feasibility and processes associated with implementing e-health solutions alongside standard clinical care, to warrant undertaking a larger more definitive clinical trial.Trial registration: Australian and New Zealand Clinical Trials Registry ACTRN12612000985886.The study is supported by beyondblue: the national depression and anxiety initiative National Priority Driven Research Program and funded through a donation from the Movember Foundation

P2X₃ Knock-Out Mice Reveal a Major Sensory Role for Urothelially Released ATP

The present study explores the possible involvement of a purinergic mechanism in mechanosensory transduction in the bladder using P2X₃ receptor knock-out (P2X₃ ⁻⁄⁻) and wild-type control (P2X₃ ⁺⁄⁺) mice. Immunohistochemistry revealed abundant nerve fibers in a suburothelial plexus in the mouse bladder that are immunoreactive to anti-P2X₃. P2X₃ -positive staining was completely absent in the subepithelial plexus of the P2X₃ ⁻⁄⁻ mice, whereas staining for calcitonin gene-related peptide and vanilloid receptor 1 receptors remained. Using a novel superfused mouse bladder–pelvic nerve preparation, we detected a release of ATP proportional to the extent of bladder distension in both P2X₃ ⁻⁄⁻ mice, whereas staining for calcitonin gene-related peptide and vanilloid receptor 1 receptors remained. Using a novel superfused mouse bladder–pelvic nerve preparation, we detected a release of ATP proportional to the extent of bladder distension in both P2X₃ ⁺⁄⁺ and P2X₃ ⁻⁄⁻ mice, although P2X₃ ⁻⁄⁻ bladder had an increased capacity compared with that of the P2X₃ ⁺⁄⁺ bladder. The activity of multifiber pelvic nerve afferents increased progressively during gradual bladder distension (at a rate of 0.1 ml/min). However, the bladder afferents from P2X₃ ⁻⁄⁻ mice showed an attenuated response to bladder distension. Mouse bladder afferents of P2X₃ ⁺⁄⁺, but not P2X₃ ⁻⁄⁻, were rapidly activated by intravesical injections of P2X agonists (ATP or α,β-methylene ATP) and subsequently showed an augmented response to bladder distension. By contrast, P2X antagonists [2′,3′-O-(2,4,6-trinitrophenyl)-ATP and pyridoxal 5-phosphate 6-azophenyl-2′,4′-disulfonic acid] and capsaicin attenuated distension-induced discharges in bladder afferents. These data strongly suggest a major sensory role for urothelially released ATP acting via P2X₃ receptors on a subpopulation of pelvic afferent fibers

Clusters, phason elasticity, and entropic stabilisation: a theory perspective

Personal comments are made about the title subjects, including: the relation of Friedel oscillations to Hume-Rothery stabilisation; how calculations may resolve the random-tiling versus ideal pictures of quasicrystals; and the role of entropies apart from tile-configurational.Comment: IOP macros; 8pp, 1 figure. In press, Phil. Mag. A (Proc. Intl. Conf. on Quasicrystals 9, Ames Iowa, May 2005

Exact Solution of an Octagonal Random Tiling Model

We consider the two-dimensional random tiling model introduced by Cockayne, i.e. the ensemble of all possible coverings of the plane without gaps or overlaps with squares and various hexagons. At the appropriate relative densities the correlations have eight-fold rotational symmetry. We reformulate the model in terms of a random tiling ensemble with identical rectangles and isosceles triangles. The partition function of this model can be calculated by diagonalizing a transfer matrix using the Bethe Ansatz (BA). The BA equations can be solved providing {\em exact} values of the entropy and elastic constants.Comment: 4 pages,3 Postscript figures, uses revte

Alloying, elemental enrichment, and interdiffusion during the growth of Ge(Si)/Si(001) quantum dots

Ge(Si)/Si(001) quantum dots produced by gas-source molecular beam epitaxy at 575 degreesC were investigated using energy-filtering transmission electron microscopy and x-ray energy dispersive spectrometry. Results show a nonuniform composition distribution in the quantum dots with the highest Ge content at the dot center. The average Ge content in the quantum dots is much higher than in the wetting layer. The quantum dot/substrate interface has been moved to the substrate side. A growth mechanism of the quantum dots is discussed based on the composition distribution and interfacial structures

Fourier Transform Scanning Tunneling Spectroscopy: the possibility to obtain constant energy maps and the band dispersion using a local measurement

We present here an overview of the Fourier Transform Scanning Tunneling spectroscopy technique (FT-STS). This technique allows one to probe the electronic properties of a two-dimensional system by analyzing the standing waves formed in the vicinity of defects. We review both the experimental and theoretical aspects of this approach, basing our analysis on some of our previous results, as well as on other results described in the literature. We explain how the topology of the constant energy maps can be deduced from the FT of dI/dV map images which exhibit standing waves patterns. We show that not only the position of the features observed in the FT maps, but also their shape can be explained using different theoretical models of different levels of approximation. Thus, starting with the classical and well known expression of the Lindhard susceptibility which describes the screening of electron in a free electron gas, we show that from the momentum dependence of the susceptibility we can deduce the topology of the constant energy maps in a joint density of states approximation (JDOS). We describe how some of the specific features predicted by the JDOS are (or are not) observed experimentally in the FT maps. The role of the phase factors which are neglected in the rough JDOS approximation is described using the stationary phase conditions. We present also the technique of the T-matrix approximation, which takes into account accurately these phase factors. This technique has been successfully applied to normal metals, as well as to systems with more complicated constant energy contours. We present results recently obtained on graphene systems which demonstrate the power of this technique, and the usefulness of local measurements for determining the band structure, the map of the Fermi energy and the constant-energy maps.Comment: 33 pages, 15 figures; invited review article, to appear in Journal of Physics D: Applied Physic