186 research outputs found

    Integrated modeling of advanced optical systems

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    This poster session paper describes an integrated modeling and analysis capability being developed at JPL under funding provided by the JPL Director's Discretionary Fund and the JPL Control/Structure Interaction Program (CSI). The posters briefly summarize the program capabilities and illustrate them with an example problem. The computer programs developed under this effort will provide an unprecedented capability for integrated modeling and design of high performance optical spacecraft. The engineering disciplines supported include structural dynamics, controls, optics and thermodynamics. Such tools are needed in order to evaluate the end-to-end system performance of spacecraft such as OSI, POINTS, and SMMM. This paper illustrates the proof-of-concept tools that have been developed to establish the technology requirements and demonstrate the new features of integrated modeling and design. The current program also includes implementation of a prototype tool based upon the CAESY environment being developed under the NASA Guidance and Control Research and Technology Computational Controls Program. This prototype will be available late in FY-92. The development plan proposes a major software production effort to fabricate, deliver, support and maintain a national-class tool from FY-93 through FY-95

    Reading on the Ropes: A Pilot Study of an Accelerated Remediation Program with Alternative High School Students

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    High school students must read to learn curriculum, yet few interventions are proven to substantially help close literacy gaps for older students with reading deficits. Students with large literacy deficits particularly benefit from explicit, systematic instruction of interventions emphasizing the structure of language (i.e., phonology, orthography, syntax, morphology, semantics, pragmatics), aspects of cognition (i.e., problem solving, attention, reasoning, and inferencing), and organization of spoken and written language. A 14-week pilot study of Readable English, a reading intervention using these structured literacy elements, provided embedded interactive orthography to scaffold online grade level content for students at two alternative high schools (N = 25). Students in the treatment group showed significant and meaningful increases in standardized tests of reading accuracy, fluency, and reading comprehension compared to minimal or no gains in the control group. Transfer effects from students using the Readable English markup to reading in standard English were demonstrated. Implications for use as accelerated remediation intervention for older adolescents are discussed

    The Benefits of Growth-Promoting Implants for Beef Cattle

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    Growth-promoting implants have been used in the cattle industry for decades. Their benefits allow cattle producers to become more sustainable by decreasing the amount of resources used. Resources such as water and land are decreased when using growth-promoting implants in beef cattle

    Binary orbits as the driver of γ-ray emission and mass ejection in classical novae

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    Classical novae are the most common astrophysical thermonuclear explosions, occurring on the surfaces of white dwarf stars accreting gas from companions in binary star systems. Novae typically expel �10,000 solar masses of material at velocities exceeding 1,000 km/s. However, the mechanism of mass ejection in novae is poorly understood, and could be dominated by the impulsive flash of the thermonuclear runaway, prolonged optically thick winds, or binary interaction with the nova envelope. Classical novae are now routinely detected in GeV gamma-rays, suggesting that relativistic particles are accelerated by strong shocks in nova ejecta. Here we present high-resolution imaging of the gamma-ray-emitting nova V959 Mon at radio wavelengths, showing that its ejecta were shaped by binary motion: some gas was expelled rapidly along the poles as a wind from the white dwarf, while denser material drifted out along the equatorial plane, propelled by orbital motion. At the interface between the equatorial and polar regions, we observe synchrotron emission indicative of shocks and relativistic particle acceleration, thereby pinpointing the location of gamma-ray production. Binary shaping of the nova ejecta and associated internal shocks are expected to be widespread among novae, explaining why many novae are gamma-ray emitters

    Use of Confocal Laser as Light Source Reveals Stomata-Autonomous Function

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    In most terrestrial plants, stomata open during the day to maximize the update of CO(2) for photosynthesis, but they close at night to minimize water loss. Blue light, among several environmental factors, controls this process. Stomata response to diverse stimuli seems to be dictated by the behaviour of neighbour stomata creating leaf areas of coordinated response. Here individual stomata of Arabidopsis leaves were illuminated with a short blue-light pulse by focusing a confocal argon laser. Beautifully, the illuminated stomata open their pores, whereas their dark-adapted neighbours unexpectedly experience no change. This induction of individual stomata opening by low fluence rates of blue light was disrupted in the phototropin1 phototropin2 (phot1 phot2) double mutant, which exhibits insensitivity of stomatal movements in blue-illuminated epidermal strips. The irradiation of all epidermal cells making direct contact with a given stoma in both wild type and phot1 phot2 plants does not trigger its movement. These results unravel the stoma autonomous function in the blue light response and illuminate the implication of PHOT1 and/or PHOT2 in such response. The micro spatial heterogeneity that solar blue light suffers in partially shaded leaves under natural conditions highlights the physiological significance of the autonomous stomatal behaviour

    When does NICE recommend the use of health technologies within a programme of evidence development?

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    This article is made available through the Brunel Open Access Publishing Fund. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Background: There is growing interest internationally in linking reimbursement decisions with recommendations for further research. In the UK, the National Institute for Health and Clinical Excellence (NICE) can issue guidance to approve the routine use of a health intervention, reject routine use or recommend use within a research programme. These latter recommendations have restricted use to ‘only in research’ (OIR) or have recommended further research alongside routine use (‘approval with research’ or AWR). However, it is not currently clear when such recommendations are likely to be made. Objectives: This study aims to identify NICE technology appraisals where OIR or AWR recommendations were made and to examine the key considerations that led to those decisions. Methods: Draft and final guidance including OIR/AWR recommendations were identified. The documents were reviewed to establish the characteristics of the technology appraisal, the cost effectiveness of the technologies, the key considerations that led to the recommendations and the types of research required. Results: In total, 29 final and 31 draft guidance documents included OIR/AWR recommendations up to January 2010. Overall, 86 % of final guidance included OIR recommendations. Of these, the majority were for technologies considered to be cost ineffective (83 %) and the majority of final guidance (66 %) specified the need for further evidence on relative effectiveness. The use of OIR/AWR recommendations is decreasing over time and they have rarely been used in appraisals conducted through the single technology appraisal process. Conclusion: NICE has used its ability to recommend technologies within research programmes, although predominantly within the multiple technology appraisal process. OIR recommendations have been most frequently issued for technologies considered cost ineffective and the most frequently cited consideration is uncertainty related to relative effectiveness. Key considerations cited for most AWR recommendations and some OIR recommendations included a need for further evidence on long-term outcomes and adverse effects of treatment.Medical Research Counci
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