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

Correction and turn completion as collaborative repair strategies in conversations following Wernicke's aphasia

This study explores repair practices deployed by the interlocutor of a speaker with Wernicke’s aphasia, their relationship to types of aphasic difficulty, and how mutual understanding and the progression of talk is maintained. A 75-year-old woman with Wernicke’s aphasia of 16 months duration and her friend video recorded 36 minutes of conversation at home. Using conversation analytic methods two patterns of other-repair by the non-aphasic interlocutor were identified. The first practice was turn completion, which occurred in the context of self-initiated word search by the person with aphasia. The second was correction in the context of trouble with reference to person or place, manifested as an erroneous word, mis-selection of a gendered pronoun, or use of a pronoun where a person’s name was expected. This correction was mainly overt, completed via a short side sequence dealing with the repair, although a few examples were embedded, where a word or phrase was replaced with a corrected form without overtly drawing attention to the correction. None of the examples included an account for the error. Unlike in typical talk, the person with aphasia did not repeat or use the corrected form in subsequent talk. For this dyad, correction and completion function as interactionally acceptable collaborative repair strategies, maintaining progressivity and a focus on topic development rather than on repair itself. There is no evidence that other-correction is dispreferred, which accords with recent findings for typical interaction but differs from other studies of aphasic talk. Correction should not be dismissed out of hand as a negative interactional practice when talking to someone with Wernicke’s aphasia

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

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

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

Radiative transfer as a Bayesian linear regression problem

Electromagnetic radiation plays a crucial role in various physical and chemical processes. Hence, almost all astrophysical simulations require some form of radiative transfer model. Despite many innovations in radiative transfer algorithms and their implementation, realistic radiative transfer models remain very computationally expensive, such that one often has to resort to approximate descriptions. The complexity of these models makes it difficult to assess the validity of any approximation and to quantify uncertainties on the model results. This impedes scientific rigour, in particular, when comparing models to observations, or when using their results as input for other models. We present a probabilistic numerical approach to address these issues by treating radiative transfer as a Bayesian linear regression problem. This allows us to model uncertainties on the input and output of the model with the variances of the associated probability distributions. Furthermore, this approach naturally allows us to create reduced-order radiative transfer models with a quantifiable accuracy. These are approximate solutions to exact radiative transfer models, in contrast to the exact solutions to approximate models that are often used. As a first demonstration, we derive a probabilistic version of the method of characteristics, a commonly-used technique to solve radiative transfer problems

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