1,453 research outputs found

    SAGA: A project to automate the management of software production systems

    Get PDF
    The Software Automation, Generation and Administration (SAGA) project is investigating the design and construction of practical software engineering environments for developing and maintaining aerospace systems and applications software. The research includes the practical organization of the software lifecycle, configuration management, software requirements specifications, executable specifications, design methodologies, programming, verification, validation and testing, version control, maintenance, the reuse of software, software libraries, documentation, and automated management

    Effects of the Lattice Discreteness on a Soliton in the Su-Schrieffer-Heeger Model

    Full text link
    In this paper we analytically study the effects of the lattice discreteness on the electron band in the SSH model. We propose a modified version of the TLM model which is derived from the SSH model using a continuum approximation. When a soliton is induced in the electron-lattice system, the electron scattering states both at the bottom of the valence band and the top of the conduction band are attracted to the soliton. This attractive force induces weakly localized electronic states at the band edges. Using the modified version of the TLM model, we have succeeded in obtaining analytical solutions of the weakly localized states and the extended states near the bottom of the valence band and the top of the conduction band. This band structure does not modify the order parameters. Our result coincides well with numerical simulation works.Comment: to be appear in J.Phys.Soc.Jpn. Figures should be requested to the author. They will be sent by the conventional airmai

    Promoting physical therapists' use of research evidence to inform clinical practice: Part 2 - A mixed methods evaluation of the PEAK program

    Get PDF
    Background: Clinicians need innovative educational programs to enhance their capacity for using research evidence to inform clinical decision-making. This paper and its companion paper introduce the Physical therapist-driven Education for Actionable Knowledge translation (PEAK) program, an educational program designed to promote physical therapists’ integration of research evidence into clinical decision-making. This, second of two, papers reports a mixed methods feasibility study of the PEAK program among physical therapists at three university-based clinical facilities. Methods: A convenience sample of 18 physical therapists participated in the six-month educational program. Mixed methods were used to triangulate results from pre-post quantitative data analyzed concurrently with qualitative data from semi-structured interviews and focus groups. Feasibility of the program was assessed by evaluating change in participants’ attitudes, self-efficacy, knowledge, skills, and self-reported behaviors in addition to their perceptions and reaction to the program. Results: All 18 therapists completed the program. The group experienced statistically significant improvements in evidence based practice self-efficacy and self-reported behavior (p < 0.001). Four themes were supported by integrated quantitative and qualitative results: 1. The collaborative nature of the PEAK program was engaging and motivating; 2. PEAK participants experienced improved self-efficacy, creating a positive cycle where success reinforces engagement with research evidence; 3. Participants’ need to understand how to interpret statistics was not fully met; 4. Participants believed that the utilization of research evidence in their clinical practice would lead to better patient outcomes. Conclusions: The PEAK program is a feasible educational program for promoting physical therapists’ use of research evidence in practice. A key ingredient seems to be guided small group work leading to a final product that guides local practice. Further investigation is recommended to assess long-term behavior change and to compare outcomes to alternative educational models.Full Tex

    Getting connected: establishing direct communication between learning developers and PhD Students with teaching responsibilities

    Get PDF
    Many PhD researchers have the opportunity to take up teaching responsibilities during their doctoral studies to enhance their employability and interest in academia. Aside from their formal teaching training, little is known about the types of resources and support from professional services that PhD students (PhDs) use to fulfil their teaching responsibilities. On the other hand, learning development is a relatively new profession within higher education. As such, there are varied perceptions on the necessity for PhDs with teaching responsibilities to engage with learning development support. This opinion piece shares the experience of a STEM UK PhD student with teaching responsibilities and a learning development practitioner when establishing support for modules taught by PhDs. Through a dialogue, the authors explore the challenges faced in the interaction between learning developers (LDs) and PhDs, in two different UK universities, and recommend how to further develop the relationship. Through this dialogue possible solutions like increasing the visibility of available LD support for PhDs with teaching responsibilities within higher education institutions (HEIs) and including LD support in PhDs teaching training were identified

    Parity Violation in Proton-Proton Scattering

    Full text link
    Measurements of parity-violating longitudinal analyzing powers (normalized asymmetries) in polarized proton-proton scattering provide a unique window on the interplay between the weak and strong interactions between and within hadrons. Several new proton-proton parity violation experiments are presently either being performed or are being prepared for execution in the near future: at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Juelich) at 230 MeV and near 1.3 GeV. These experiments are intended to provide stringent constraints on the set of six effective weak meson-nucleon coupling constants, which characterize the weak interaction between hadrons in the energy domain where meson exchange models provide an appropriate description. The 221 MeV is unique in that it selects a single transition amplitude (3P2-1D2) and consequently constrains the weak meson-nucleon coupling constant h_rho{pp}. The TRIUMF 221 MeV proton-proton parity violation experiment is described in some detail. A preliminary result for the longitudinal analyzing power is Az = (1.1 +/-0.4 +/-0.4) x 10^-7. Further proton-proton parity violation experiments are commented on. The anomaly at 6 GeV/c requires that a new multi-GeV proton-proton parity violation experiment be performed.Comment: 13 Pages LaTeX, 5 PostScript figures, uses espcrc1.sty. Invited talk at QULEN97, International Conference on Quark Lepton Nuclear Physics -- Nonperturbative QCD Hadron Physics & Electroweak Nuclear Processes --, Osaka, Japan May 20--23, 199

    Parity Violation in Proton-Proton Scattering at 221 MeV

    Full text link
    TRIUMF experiment 497 has measured the parity violating longitudinal analyzing power, A_z, in pp elastic scattering at 221.3 MeV incident proton energy. This paper includes details of the corrections, some of magnitude comparable to A_z itself, required to arrive at the final result. The largest correction was for the effects of first moments of transverse polarization. The addition of the result, A_z=(0.84 \pm 0.29 (stat.) \pm 0.17 (syst.)) \times 10^{-7}, to the pp parity violation experimental data base greatly improves the experimental constraints on the weak meson-nucleon coupling constants h^{pp}_\rho and h^{pp}_\omega, and has implications for the interpretation of electron parity violation experiments.Comment: 17 pages RevTeX, 14 PostScript figures. Revised version with additions suggested by Phys. Rev.

    The Correlation of Retinal Nerve Fiber Layer Thickness With Blood Pressure in a Chinese Hypertensive Population

    Get PDF
    To investigate the association between retinal nerve fiber layer (RNFL) thickness and blood pressure (BP) in subjects with systemic hypertension. Subjects with systemic hypertension on anti-hypertensive medications were screened by fundus photography and referred for glaucoma work-up if there was enlarged vertical cup-to-disc (VCDR) ratio ≥0.6, VCDR asymmetry ≥0.2, or optic disc hemorrhage. Workup included a complete ophthalmological examination, Humphrey visual field test, and RNFL thickness measurement by optical coherence tomography. The intraocular pressure (IOP) and RNFL thicknesses (global and quadrant) were averaged from both eyes and the means were correlated with: the systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP) using Pearson correlation. Among 4000 screened hypertensive subjects, 133 were referred for glaucoma workup and 110 completed the workup. Of the 4000 screened subjects, 1.3% had glaucoma (0.9% had normal tension glaucoma [NTG], 0.2% had primary open angle glaucoma, and 0.2% had primary angle closure glaucoma), whereas 0.3% were NTG suspects. The SBP was negatively correlated with the mean superior RNFL thickness (P=0.01). The DBP was negatively correlated with the mean global (P=0.03), superior (P=0.02), and nasal (P=0.003) RNFL thickness. The MAP was negatively correlated with the mean global (P=0.01), superior (P=0.002), and nasal (P=0.004) RNFL thickness while positively correlated with the mean IOP (P=0.02). In medically treated hypertensive subjects, glaucoma was present in 1.3%, with NTG being most prevalent. MAP control may help with IOP lowering and RNFL preservation, although future prospective studies will be needed. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.published_or_final_versio

    Insights into the mechanism of cell death induced by saporin delivered into cancer cells by an antibody fusion protein targeting the transferrin receptor 1

    Get PDF
    We previously developed an antibody-avidin fusion protein (ch128.1Av) that targets the human transferrin receptor 1 (TfR1) and exhibits direct cytotoxicity against malignant B cells in an iron-dependent manner. ch128.1Av is also a delivery system and its conjugation with biotinylated saporin (b-SO6), a plant ribosome-inactivating toxin, results in a dramatic iron-independent cytotoxicity, both in malignant cells that are sensitive or resistant to ch128.1Av alone, in which the toxin effectively inhibits protein synthesis and triggers caspase activation. We have now found that the ch128.1Av/b-SO6 complex induces a transcriptional response consistent with oxidative stress and DNA damage, a response that is not observed with ch128.1Av alone. Furthermore, we show that the antioxidant N-acetylcysteine partially blocks saporin-induced apoptosis suggesting that oxidative stress contributes to DNA damage and ultimately saporin-induced cell death. Interestingly, the toxin was detected in nuclear extracts by immunoblotting, suggesting the possibility that saporin might induce direct DNA damage. However, confocal microscopy did not show a clear and consistent pattern of intranuclear localization. Finally, using the long-term culture-initiating cell assay we found that ch128.1Av/b-SO6 is not toxic to normal human hematopoietic stem cells suggesting that this critical cell population would be preserved in therapeutic interventions using this immunotoxin.Fil: Daniels Wells, Tracy R.. University of California; Estados Unidos de América;Fil: Helguera, Gustavo Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. University of California; Estados Unidos de América;Fil: Rodríguez, José A.. University of California; Estados Unidos de América;Fil: Leoh, Lai Sum. University of California; Estados Unidos de América;Fil: Erb, Michael A.. University of California; Estados Unidos de América;Fil: Diamante, Graciel. University of California; Estados Unidos de América;Fil: Casero, David. University Of California; Estados Unidos de América;Fil: Pellegrini, Mateo. University of California; Estados Unidos de América;Fil: Martinez Maza, Otoniel. University of California; Estados Unidos de América;Fil: Penichet, Manuel L.. University of California; Estados Unidos de América

    Parity Violation in Proton-Proton Scattering at 221 MeV

    Full text link
    The parity-violating longitudinal analyzing power, Az, has been measured in pp elastic scattering at an incident proton energy of 221 MeV. The result obtained is Az =(0.84 +/- 0.29 (stat.) +/- 0.17 (syst.)) x 10^{-7}. This experiment is unique in that it selects a single parity violating transition amplitude, 3P2-1D2, and consequently directly constrains the weak meson-nucleon coupling constant h^pp_rho When this result is taken together with the existing pp parity violation data, the weak meson-nucleon coupling constants h^pp_rho and h^pp_omega can, for the first time, both be determined.Comment: 8 pages RevTeX4, 3 PostScript figures. Conclusion revised. New information about weak coupling constants adde

    Hydrogen-doped Brookite TiO2 Nanobullets Array as a Novel Photoanode for Efficient Solar Water Splitting

    Get PDF
    As a representative photocatalyst for photoelectrochemical solar water splitting, TiO2 has been intensively studied but most researches have focused on the rutile and anatsase phases because brookite, another important crystalline polymorph of TiO2, rarely exists in nature and is difficult to synthesize. In this work, hydrogen doped brookite (H:brookite) nanobullet arrays were synthesized via a well-designed solution reaction for the first time. H:brookite shows highly improved PEC properties with excellent stability, enhanced photocurrent, and significantly high Faradaic efficiency for overall solar water splitting. To support the experimental data, ab initio density functional theory calculations were also conducted. At the interstitial doping site that has minimum formation energy, the hydrogen atoms act as shallow donors and exist as H+. which has the minimum formation energy among three states of hydrogen (H+. H0, and H-). The calculated density of states of H:brookite shows a narrowed bandgap and an increased electron density compared to the pristine brookite. The combined experimental and theoretical results provide frameworks for the exploration of the PEC properties of doped brookite and extend our knowledge regarding the undiscovered properties of brookite of TiO2.ope
    corecore