660 research outputs found

    Orbit transfer rocket engine integrated control and health monitoring system technology readiness assessment

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    The objectives of this task were to: (1) estimate the technology readiness of an integrated control and health monitoring (ICHM) system for the Aerojet 7500 lbF Orbit Transfer Vehicle engine preliminary design assuming space based operations; and (2) estimate the remaining cost to advance this technology to a NASA defined 'readiness level 6' by 1996 wherein the technology has been demonstrated with a system validation model in a simulated environment. The work was accomplished through the conduct of four subtasks. In subtask 1 the minimally required functions for the control and monitoring system was specified. The elements required to perform these functions were specified in Subtask 2. In Subtask 3, the technology readiness level of each element was assessed. Finally, in Subtask 4, the development cost and schedule requirements were estimated for bringing each element to 'readiness level 6'

    Space Communications: Theory and Applications. Volume 3: Information Processing and Advanced Techniques. A Bibliography, 1958 - 1963

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    Annotated bibliography on information processing and advanced communication techniques - theory and applications of space communication

    Adaptation of a Vocabulary Test from British Sign Language to American Sign Language

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    This study describes the adaptation process of a vocabulary knowledge test for British Sign Language (BSL) into American Sign Language (ASL) and presents results from the first round of pilot testing with twenty deaf native ASL signers. The web-based test assesses the strength of deaf children’s vocabulary knowledge by means of different mappings of phonological form and meaning of signs. The adaptation from BSL to ASL involved nine stages, which included forming a panel of deaf/hearing experts, developing a set of new items and revising/replacing items considered ineffective, and piloting the new version. Results provide new evidence in support of the use of this methodology for assessing sign language, making a useful contribution toward the availability of tests to assess deaf children’s signed language skills

    Microfabricated Hydrogen Sensor Technology for Aerospace and Commercial Applications

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    Leaks on the Space Shuttle while on the Launch Pad have generated interest in hydrogen leak monitoring technology. An effective leak monitoring system requires reliable hydrogen sensors, hardware, and software to monitor the sensors. The system should process the sensor outputs and provide real-time leak monitoring information to the operator. This paper discusses the progress in developing such a complete leak monitoring system. Advanced microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC) and Gencorp Aerojet (Aerojet). Changes in the hydrogen concentrations are detected using a PdAg on silicon Schottky diode structure. Sensor temperature control is achieved with a temperature sensor and heater fabricated onto the sensor chip. Results of the characterization of these sensors are presented. These sensors can detect low concentrations of hydrogen in inert environments with high sensitivity and quick response time. Aerojet is developing the hardware and software for a multipoint leak monitoring system designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Work has commenced on integrating the NASA LeRC-CWRU hydrogen sensors with the Aerojet designed monitoring system. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. Possible commercialization of the system will also be discussed

    Spirulina Promotes Stem Cell Genesis and Protects against LPS Induced Declines in Neural Stem Cell Proliferation

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    Adult stem cells are present in many tissues including, skin, muscle, adipose, bone marrow, and in the brain. Neuroinflammation has been shown to be a potent negative regulator of stem cell and progenitor cell proliferation in the neurogenic regions of the brain. Recently we demonstrated that decreasing a key neuroinflammatory cytokine IL-1β in the hippocampus of aged rats reversed the age-related cognitive decline and increased neurogenesis in the age rats. We also have found that nutraceuticals have the potential to reduce neuroinflammation, and decrease oxidative stress. The objectives of this study were to determine if spirulina could protect the proliferative potential of hippocampal neural progenitor cells from an acute systemic inflammatory insult of lipopolysaccharide (LPS). To this end, young rats were fed for 30 days a control diet or a diet supplemented with 0.1% spirulina. On day 28 the rats were given a single i.p. injection of LPS (1 mg/kg). The following day the rats were injected with BrdU (50 mg/kg b.i.d. i.p.) and were sacrificed 24 hours after the first injection of BrdU. Quantification of the BrdU positive cells in the subgranular zone of the dentate gyrus demonstrated a decrease in proliferation of the stem/progenitor cells in the hippocampus as a result of the LPS insult. Furthermore, the diet supplemented with spirulina was able to negate the LPS induced decrease in stem/progenitor cell proliferation. In a second set of studies we examined the effects of spirulina either alone or in combination with a proprietary formulation (NT-020) of blueberry, green tea, vitamin D3 and carnosine on the function of bone marrow and CD34+ cells in vitro. Spirulina had small effects on its own and more than additive effects in combination with NT-020 to promote mitochondrial respiration and/or proliferation of these cells in culture. When examined on neural stem cells in culture spirulina increased proliferation at baseline and protected against the negative influence of TNFα to reduce neural stem cell proliferation. These results support the hypothesis that a diet enriched with spirulina and other nutraceuticals may help protect the stem/progenitor cells from insults

    Let\u27s talk about antibiotics: A randomised trial of two interventions to reduce antibiotic misuse

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    BACKGROUND: Children with acute respiratory tract infections (ARTIs) receive ≈11.4 million unnecessary antibiotic prescriptions annually. A noted contributor is inadequate parent-clinician communication, however, efforts to reduce overprescribing have only indirectly targeted communication or been impractical. OBJECTIVES: Compare two feasible (higher vs lower intensity) interventions for enhancing parent-clinician communication on the rate of inappropriate antibiotic prescribing. DESIGN: Multisite, parallel group, cluster randomised comparative effectiveness trial. Data collected between March 2017 and March 2019. SETTING: Academic and private practice outpatient clinics. PARTICIPANTS: Clinicians (n=41, 85% of eligible approached) and 1599 parent-child dyads (ages 1-5 years with ARTI symptoms, 71% of eligible approached). INTERVENTIONS: All clinicians received 20 min ARTI diagnosis and treatment education. Higher intensity clinicians received an additional 50 min communication skills training. All parents viewed a 90 second antibiotic education video. MAIN OUTCOMES AND MEASURES: Inappropriate antibiotic treatment was assessed via blinded medical record review by study clinicians and a priori defined as prescriptions for the wrong diagnosis or use of the wrong agent. Secondary outcomes were revisits, adverse drug reactions (both assessed 2 weeks after the visit) and parent ratings of provider communication, shared decision-making and visit satisfaction (assessed at end of the visit on Likert-type scales). RESULTS: Most clinicians completed the study (n=38, 93%), were doctors (n=25, 66%), female (n=30, 78%) and averaged 8 years in practice. All parent-child dyad provided data for the main outcome (n=855 (54%) male, n=1043 (53%) CONCLUSIONS AND RELEVANCE: Rate of inappropriate prescribing was low in both arms. Clinician education coupled with parent education may be sufficient to yield low inappropriate antibiotic prescribing rates. The absence of a significant difference between groups indicates that communication principles previously thought to drive inappropriate prescribing may need to be re-examined or may not have as much of an impact in practices where prescribing has improved in recent years. TRIAL REGISTRATION NUMBER: NCT03037112

    Transitional justice and the political 'work' of domestic tourism

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    The relationship between tourism and transitional justice is little-researched. This paper explores the importance of domestic tourism for enabling citizens to encounter and engage with wider transitional justice projects. This issue is explored with reference to a memorial museum in Romania which interprets political violence and state repression. Semi-structured interviews with 52 domestic tourists were undertaken (using purposive sampling to select participants) and the interviews were analysed using thematic analysis. Most visitors reported general sightseeing motives for visiting the museum and may not have anticipated engaging with transitional justice messages. However, their engagement went beyond sightseeing in a range of ways. Visitors participated in acts of memory-work, acknowledged the victims of repression, and recognized the core message of transitional justice – “never again”. They also reflected on the relationship between the recent past and the present, and recognized the role of the museum as a resource for future generations. These experiences were shared by those who had lived through state repression and those who had not. The findings indicate that domestic tourism is a meaningful but overlooked context through which citizens can engage with broader transitional justice projects

    Listening for policy change: How the voices of disabled people shaped Australia’s National Disability Insurance Scheme

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    Voice has become an important yet ambivalent tool for the recognition of disability. The transformative potential of voice is dependent on a political commitment to listening to disabled people. To focus on listening redirects accountability for social change from disabled people to the ableist norms, institutions and practices that structure which voices can be heard in policy debates. In this paper, I use disability theory on voice and political theory on listening to examine policy documents for the National Disability Insurance Scheme in light of claims made by the disability movement. Although my study finds some evidence of openness in the policy development stage, the scheme falls short of valuing the diverse voices of disabled people as partners in shared dialogue
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