Track and capture of the orbiter with the space station remote manipulator system

Results of the first study using the real-time, man-in-the-loop Systems Engineering Simulator (SES) for track and capture of the Space Shuttle Orbiter with the space station manipulator are presented. The objectives include evaluation of the operational coordination required between the orbiter pilot and the space station manipulator operator, evaluation of the locations and required number of closed-circuit television cameras, and evaluation of the orbiter grapple fixture clearance geometry. The SES is a premium quality real-time facility with full fidelity orbiter and space station crew workstations and cockpits

User's manual for the Shuttle Electric Power System analysis computer program (SEPS), volume 2 of program documentation

The Shuttle Electric Power System Analysis SEPS computer program which performs detailed load analysis including predicting energy demands and consumables requirements of the shuttle electric power system along with parameteric and special case studies on the shuttle electric power system is described. The functional flow diagram of the SEPS program is presented along with data base requirements and formats, procedure and activity definitions, and mission timeline input formats. Distribution circuit input and fixed data requirements are included. Run procedures and deck setups are described

Polarization properties of OH masers in AGB and post-AGB stars

Context: Ground-state OH maser emission from late-type stars is usually polarized and remains a powerful probe of the magnetic field structure in the outer regions of circumstellar envelopes if observed with high angular and spectral resolutions. Observations in all four Stokes parameters are quite sparse and this is the most thorough, systematic study published to date. Aims: We aim to determine polarization properties of OH masers in an extensive sample of stars that show copious mass loss and search for candidate objects that are well-suited for high angular resolution studies. Methods: Full-polarization observations of the OH 1612 and 1667 MHz maser transitions were carried out for a sample of 117 AGB and post-AGB stars. Several targets were also observed in the 1665 MHz line. Results: Polarized features occur in more than 75% of the sources in the complete sample and there is no intrinsic difference in the occurrence of polarized emission between the three classes of objects of different infrared characteristics. The highest fractional polarization occurs for the post-AGB+PN and the Mira+SR classes at 1612 and 1667 MHz, respectively. Differences in the fractional polarization between the sources at different evolutionary stages appear to be related to depolarization caused by blending. The alignment of the polarization angles at the extreme sides of the shell implies a regular structure of the magnetic field of a strength of 0.3-2.3 mG. Conclusions: Polarized OH maser features are widespread in AGB and post-AGB stars. The relationship between the circular and linear fractional polarizations for a representative sample are consistent with the standard models of polarization for the Zeeman splitting higher than the Doppler line width, whereas the polarized features are the sigma components.Comment: Accepted for publication in Astronomy and Astrophysics. A version with appendices (Tab. A.1 and Fig. B.1) can be downloaded from http://paulo.astro.uni.torun.pl/~pw/arXiv_

Molecular diversity and population structure at the Cytochrome P450 3A5 gene in Africa.

Cytochrome P450 3A5 (CYP3A5) is an enzyme involved in the metabolism of many therapeutic drugs. CYP3A5 expression levels vary between individuals and populations, and this contributes to adverse clinical outcomes. Variable expression is largely attributed to four alleles, CYP3A5*1 (expresser allele); CYP3A5*3 (rs776746), CYP3A5*6 (rs10264272) and CYP3A5*7 (rs41303343) (low/non-expresser alleles). Little is known about CYP3A5 variability in Africa, a region with considerable genetic diversity. Here we used a multi-disciplinary approach to characterize CYP3A5 variation in geographically and ethnically diverse populations from in and around Africa, and infer the evolutionary processes that have shaped patterns of diversity in this gene. We genotyped 2538 individuals from 36 diverse populations in and around Africa for common low/non-expresser CYP3A5 alleles, and re-sequenced the CYP3A5 gene in five Ethiopian ethnic groups. We estimated the ages of low/non-expresser CYP3A5 alleles using a linked microsatellite and assuming a step-wise mutation model of evolution. Finally, we examined a hypothesis that CYP3A5 is important in salt retention adaptation by performing correlations with ecological data relating to aridity for the present day, 10,000 and 50,000 years ago

Program manual for the Shuttle Electric Power System analysis computer program (SEPS), volume 1 of program documentation

The Shuttle Electric Power System (SEPS) computer program is considered in terms of the program manual, programmer guide, and program utilization. The main objective is to provide the information necessary to interpret and use the routines comprising the SEPS program. Subroutine descriptions including the name, purpose, method, variable definitions, and logic flow are presented

Ghost pill: knowledge and awareness of this phenomenon among health care professionals

Background: Slow release (SR) drug formulations associated with the passage of intact tablet like object in faeces sometimes known as the “ghost pill” have been in the market for many years. Anecdotal evidence suggests that few health care professionals are aware of this phenomenon. Our study aims were to find out what proportion of health care professionals was aware of the ghost pill phenomena and what drug formulations and specific drugs were associated with it.Methods: A survey was conducted among health care professionals at three hospital sights in the West Midlands, UK. The subjects included doctors, nursing staff, pharmacists, and other allied professionals involved in patient care.Results: A total of 321 health care professionals were included in the final analysis. Very few, 12.8% (41) have heard of the ghost pill phenomenon and a further 14 (4.4%) have come across of a patient who has experienced it. Only 13 (4%) correctly associated the phenomenon with SR drug formulations.Conclusion: Our survey has shown that the ghost pill phenomenon, a normal outcome of a novel way of delivering orally taken SR drugs, is not well-known among health care professionals. Lack of awareness of it has implications to trainers, medical and nonmedical prescribers and nursing staff working with patients who are taking these medications. Lack of awareness among health care staff, may result in relevant information not being shared with patients at the time of prescribing or when patients enquires of it

Real-time RMS active damping augmentation: Heavy and very light payload evaluations

Controls-Structures Integration Technology has been applied to the Space Shuttle Remote Manipulator System (RMS) to improve on-orbit performance. The objective was to actively damp undesired oscillatory motions of the RMS following routine payload maneuvering and Shuttle attitude control thruster firings. Simulation of active damping was conducted in the real-time, man-in-the-loop Systems Engineering Simulator at NASA's Johnson Space Center. The simulator was used to obtain qualitative and quantitative data on active damping performance from astronaut operators. Using a simulated three-axis accelerometer mounted on the RMS, 'sensed' vibration motions were used to generate joint motor commands that reduced the unwanted oscillations. Active damping of the RMS with heavy and light attached payloads was demonstrated in this study. Five astronaut operators examined the performance of active damping following operator commanded RMS maneuvers and Shuttle thruster firings. Noticeable improvements in the damping response of the RMS with the heavy, Hubble Space Telescope payload and the very light, astronaut in Manipulator Foot Restraint payload were observed. The potential of active damping to aid in precisely maneuvering payloads was deemed significant

Extrapleural pneumonectomy versus pleurectomy/decortication in the surgical management of malignant pleural mesothelioma: Results in 663 patients

ObjectiveThe optimal procedure for resection of malignant pleural mesothelioma is controversial, partly because previous analyses include small numbers of patients. We performed a multi-institutional study to increase statistical power to detect significant differences in outcome between extrapleural pneumonectomy and pleurectomy/decortication.MethodsPatients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy or pleurectomy/decortication at 3 institutions were identified. Survival and prognostic factors were analyzed by the Kaplan–Meier method, log-rank test, and Cox proportional hazards analysis.ResultsFrom 1990 to 2006, 663 consecutive patients (538 men and 125 women) underwent resection. The median age was 63 years (range, 26–93 years). The operative mortality was 7% for extrapleural pneumonectomy (n = 27/385) and 4% for pleurectomy/decortication (n = 13/278). Significant survival differences were seen for American Joint Committee on Cancer stages 1 to 4 (P < .001), epithelioid versus non-epithelioid histology (P < .001), extrapleural pneumonectomy versus pleurectomy/decortication (P < .001), multimodality therapy versus surgery alone (P < .001), and gender (P < .001). Multivariate analysis demonstrated a hazard rate of 1.4 for extrapleural pneumonectomy (P < .001) controlling for stage, histology, gender, and multimodality therapy.ConclusionPatients who underwent pleurectomy/decortication had a better survival than those who underwent extrapleural pneumonectomy; however, the reasons are multifactorial and subject to selection bias. At present, the choice of resection should be tailored to the extent of disease, patient comorbidities, and type of multimodality therapy planned

Molecular line mapping of the giant molecular cloud associated with RCW 106 - II. Column density and dynamical state of the clumps

We present a fully sampled C^{18}O (1-0) map towards the southern giant molecular cloud (GMC) associated with the HII region RCW 106, and use it in combination with previous ^{13}CO (1-0) mapping to estimate the gas column density as a function of position and velocity. We find localized regions of significant ^{13}CO optical depth in the northern part of the cloud, with several of the high-opacity clouds in this region likely associated with a limb-brightened shell around the HII region G333.6-0.2. Optical depth corrections broaden the distribution of column densities in the cloud, yielding a log-normal distribution as predicted by simulations of turbulence. Decomposing the ^{13}CO and C^{18}O data cubes into clumps, we find relatively weak correlations between size and linewidth, and a more sensitive dependence of luminosity on size than would be predicted by a constant average column density. The clump mass spectrum has a slope near -1.7, consistent with previous studies. The most massive clumps appear to have gravitational binding energies well in excess of virial equilibrium; we discuss possible explanations, which include magnetic support and neglect of time-varying surface terms in the virial theorem. Unlike molecular clouds as a whole, the clumps within the RCW 106 GMC, while elongated, appear to show random orientations with respect to the Galactic plane.Comment: 17 pages, to appear in MNRA

Screening and supporting through schools: educational experiences and needs of adolescents living with HIV in a South African cohort

BACKGROUND: Many adolescents living with HIV remain disconnected from care, especially in high-prevalence settings. Slow progressors-adolescents infected perinatally who survive without access to lifesaving treatment-remain unidentified and disconnected from heath systems, especially in high-prevalence settings. This study examines differences in educational outcomes for ALHIV, in order to i) identify educational markers for targeting HIV testing, counselling and linkages to care, and ii) to identify essential foci of educational support for ALHIV. METHODS: Quantitative interviews with N = 1063 adolescents living with HIV and N = 456 HIV-free community control adolescents (10-19 year olds) included educational experiences (enrolment, fee-free school, school feeding schemes, absenteeism, achievement), physical health, cognitive difficulties, mental health challenges (depression, stigma, and trauma), missing school to attend clinic appointments, and socio-demographic characteristics. Voluntary informed consent was obtained from adolescents and caregivers (when adolescent < 18 years old). Analyses included multivariate logistic regressions, controlling for socio-demographic covariates, and structural equation modelling using STATA15. RESULTS: ALHIV reported accessing educational services (enrolment, free schools, school feeding schemes) at the same rates as other adolescents (94, 30, and 92% respectively), suggesting that school is a valuable site for identification. Living with HIV was associated with poorer attendance (aOR = 1.7 95%CI1.1-2.6) and educational delay (aOR1.7 95%CI1.3-2.2). Adolescents who reported educational delay were more likely to be older, male, chronically sick and report more cognitive difficulties. A path model with excellent model fit (RMSEA = 0.027, CFI 0.984, TLI 0.952) indicated that living with HIV was associated with a series of poor physical, mental and cognitive health issues which led to worse educational experiences. CONCLUSION: Schools may provide an important opportunity to identify unreached adolescents living with HIV and link them into care, focusing on adolescents with poor attendance, frequent sickness, low mood and slow learning. Key school-based markers for identifying unreached adolescents living with HIV may be low attendance, frequent sickness, low mood and slow learning. Improved linkages to care for adolescents living with HIV, in particular educational support services, are necessary to support scholastic achievement and long-term well-being, by helping them to cope with physical, emotional and cognitive difficulties