338 research outputs found

    Orbit Determination Toolbox

    Get PDF
    The Orbit Determination Toolbox is an orbit determination (OD) analysis tool based on MATLAB and Java that provides a flexible way to do early mission analysis. The toolbox is primarily intended for advanced mission analysis such as might be performed in concept exploration, proposal, early design phase, or rapid design center environments. The emphasis is on flexibility, but it has enough fidelity to produce credible results. Insight into all flight dynamics source code is provided. MATLAB is the primary user interface and is used for piecing together measurement and dynamic models. The Java Astrodynamics Toolbox is used as an engine for things that might be slow or inefficient in MATLAB, such as high-fidelity trajectory propagation, lunar and planetary ephemeris look-ups, precession, nutation, polar motion calculations, ephemeris file parsing, and the like. The primary analysis functions are sequential filter/smoother and batch least-squares commands that incorporate Monte-Carlo data simulation, linear covariance analysis, measurement processing, and plotting capabilities at the generic level. These functions have a user interface that is based on that of the MATLAB ODE suite. To perform a specific analysis, users write MATLAB functions that implement truth and design system models. The user provides his or her models as inputs to the filter commands. The software provides a capability to publish and subscribe to a software bus that is compliant with the NASA Goddard Mission Services Evolution Center (GMSEC) standards, to exchange data with other flight dynamics tools to simplify the flight dynamics design cycle. Using the publish and subscribe approach allows for analysts in a rapid design center environment to seamlessly incorporate changes in spacecraft and mission design into navigation analysis and vice versa

    Effect of continuous light on spermatogenesis and testicular steroidogenesis in rats: Possible involvement of alpha 2u-globulin

    Get PDF
    ABSTRACT Male rats exposed to continous light for 70days showed an increased weights of testis, accessory sex organs, serum levels of FSH, LH, testosterone, testicular 17β-hydroxysteroid dehydrogenase (17β-HSD) activity and alpha 2u-globulin, while 3β-hydroxysteroid dehydrogenase activity showed no signifi cant changes. Prolonged light exposure also stimulated sepermatogenesis in rats. These results suggest that alpha 2u-globulin possibly stimutates the male gonad by inducing pituitary gonadotropins in continuous light-exposed rats. Keywords: Constant light, alpha 2u-globulin, testis. urine. HORMONE ASSAY Serum FSH and LH were measured by radioimmunoassay according to the method of Moudgal and Madhwa Raj

    Characteristics of Patients with Late-Stage Parkinsonism who are Nursing Home Residents Compared with those Living at Home

    Get PDF
    OBJECTIVES: To determine clinical characteristics and treatment complications of patients with late-stage Parkinsonism living in nursing homes compared with those living at home. DESIGN: Cross-sectional analysis. SETTING AND PARTICIPANTS: This study is an analysis of 692 patients with late stage Parkinsonism recruited to an in-depth international study, Care of Late-Stage Parkinsonism (CLaSP). MEASURES: Sociodemographic characteristics were compared between patients who were living in a nursing home (n = 194) and those living at home (n = 498). Clinical assessments included the Unified Parkinson's Disease Rating Scale (UPDRS), the nonmotor symptom scale, the neuropsychiatric inventory, and a structured interview of patients and carers. Predictors of nursing home status were determined in a multivariate analysis. RESULTS: Nursing home placement was strongly associated with more severe cognitive impairment, worse UPDRS motor scores and disability, and with being unmarried and older. Although nursing home residents had significantly higher axial scores, falls were less common. Despite similar levodopa equivalence doses, they had less dyskinesia. Nonmotor symptom burden, particularly delusion, hallucination, and depression scores were higher in nursing home residents, and they were more frequently on psychotropic medication. They had lower rates of dopamine agonist use and lower rates of impulse control disorders. In multivariate analysis, being unmarried, presence of cognitive impairment, worse disease severity as assessed on the UPDRS parts II and III, severity of delusions, and lower rate of dyskinesia were associated with nursing home placement. CONCLUSIONS AND IMPLICATIONS: These clinical characteristics suggest that in patients with Parkinsonsim who are nursing home residents, presence of cognitive impairment and delusions particularly add to the higher overall symptom burden, and more often require specific treatments, including clozapine. Despite similar levodopa equivalent daily dose, motor severity is higher, and dyskinesias, indicative of a response to levodopa, are less common. Falls, however, also occur less commonly, and dopamine agonists are less frequently used, with lower rates of impulse control disorder

    Raman Fingerprint of Pressure-Induced Phase Transitions in TiS3Nanoribbons: Implications for Thermal Measurements under Extreme Stress Conditions

    Full text link
    Two-dimensional layered trichalcogenide materials have recently attracted the attention of the scientific community because of their robust mechanical and thermal properties and applications in opto- and nanoelectronics devices. We report the pressure dependence of out-of-plane Ag Raman modes in high quality few-layer titanium trisulfide (TiS3) nanoribbons grown using a direct solid-gas reaction method and infer their cross-plane thermal expansion coefficient. Both mechanical stability and thermal properties of the TiS3 nanoribbons are elucidated by using phonon-spectrum analyses. Raman spectroscopic studies at high pressure (up to 34 GPa) using a diamond anvil cell identify four prominent Ag Raman bands; a band at 557 cm-1 softens under compression, and others at 175, 300, and 370 cm-1 show normal hardening. Anomalies in phonon mode frequencies and excessive broadening in line width of the soft phonon about 13 GPa are attributed to the possible onset of a reversible structural transition. A complete structural phase transition at 43 GPa is inferred from the Ag soft mode frequency (557 cm-1) versus pressure extrapolation curve, consistent with recently reported theoretical predictions. Using the experimental mode Grüneisen parameters γi of Raman modes, we estimated the cross-plane thermal expansion coefficient Cv of the TiS3 nanoribbons at ambient phase to be 1.321 × 10-6 K-1. The observed results are expected to be useful in calibration and performance of next-generation nanoelectronics and optical devices under extreme stress condition
    corecore