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5,288 results on '"JOHNSTON M"'

154. The Mars Reconnaissance Orbiter Mission: 10 Years of Exploration from Mars Orbit

Author

Johnston, M. Daniel and Zurek, Richard W

Subjects
Lunar And Planetary Science And Exploration
Abstract

The Mars Reconnaissance Orbiter ( MRO ) entered Mars orbit on March 10, 2006. After five months of aerobraking, a series of propulsive maneuvers were used to establish the desired low -altitude science orbit. The spacecraft has been on station in its 255 x 320 k m, sun -synchronous (approximately 3 am -pm ), primary science orbit since September 2006 performing both scientific and Mars programmatic support functions. This paper will provide a summary of the major achievements of the mission to date and the major flight activities planned for the remainder of its third Extended Mission (EM3). Some of the major flight challenges the flight team has faced are also discussed.

Published
2016

157. Summary Report for the Technical Interchange Meeting on Development of Baseline Material Properties and Design Guidelines for In-Space Manufacturing Activities

Author

Prater, T. J, Bean, Q. A, Werkheiser, N. J, Johnston, M. M, Ordonez, E. A, Ledbetter, F. E, Risdon, D. L, Stockman, T. J, Sandridge, S. K. R, and Nelson, G. M

Subjects
Spacecraft Design, Testing And Performance
Abstract

NASA Marshall Space Flight Center (MSFC) and the Agency as a whole are currently engaged in a number of in-space manufacturing (ISM) activities that have the potential to reduce launch costs, enhance crew safety, and provide the capabilities needed to undertake long-duration spaceflight. The recent 3D Printing in Zero-G experiment conducted on board the International Space Station (ISS) demonstrated that parts of acrylonitrile butadiene styrene (ABS) plastic can be manufactured in microgravity using fused deposition modeling (FDM). This project represents the beginning of the development of a capability that is critical to future NASA missions. Current and future ISM activities will require the development of baseline material properties to facilitate design, analysis, and certification of materials manufactured using in-space techniques. The purpose of this technical interchange meeting (TIM) was to bring together MSFC practitioners and experts in materials characterization and development of baseline material properties for emerging technologies to advise the ISM team as we progress toward the development of material design values, standards, and acceptance criteria for materials manufactured in space. The overall objective of the TIM was to leverage MSFC's shared experiences and collective knowledge in advanced manufacturing and materials development to construct a path forward for the establishment of baseline material properties, standards development, and certification activities related to ISM. Participants were asked to help identify research and development activities that will (1) accelerate acceptance and adoption of ISM techniques among the aerospace design community; (2) benefit future NASA programs, commercial technology developments, and national needs; and (3) provide opportunities and avenues for further collaboration.

Published
2016

162. Behavior Change Techniques and Their Mechanisms of Action: A Synthesis of Links Described in Published Intervention Literature

Author

Carey, R.N., Connell, L.E., Johnston, M., Rothman, A.J., Bruin, M. de, Kelly, M.P., and Michie, S.

Subjects
Healthcare improvement science Radboud Institute for Health Sciences [Radboudumc 18]
Abstract

Contains fulltext : 208462.pdf (Publisher’s version ) (Open Access) BACKGROUND: Despite advances in behavioral science, there is no widely shared understanding of the "mechanisms of action" (MoAs) through which individual behavior change techniques (BCTs) have their effects. Cumulative progress in the development, evaluation, and synthesis of behavioral interventions could be improved by identifying the MoAs through which BCTs are believed to bring about change. PURPOSE: This study aimed to identify the links between BCTs and MoAs described by authors of a corpus of published literature. METHODS: Hypothesized links between BCTs and MoAs were extracted by two coders from 277 behavior change intervention articles. Binomial tests were conducted to provide an indication of the relative frequency of each link. RESULTS: Of 77 BCTs coded, 70 were linked to at least one MoA. Of 26 MoAs, all but one were linked to at least one BCT. We identified 2,636 BCT-MoA links in total (mean number of links per article = 9.56, SD = 13.80). The most frequently linked MoAs were "Beliefs about Capabilities" and "Intention." Binomial test results identified up to five MoAs linked to each of the BCTs (M = 1.71, range: 1-5) and up to eight BCTs for each of the MoAs (M = 3.63, range: 1-8). CONCLUSIONS: The BCT-MoA links described by intervention authors and identified in this extensive review present intervention developers and reviewers with a first level of systematically collated evidence. These findings provide a resource for the development of theory-based interventions, and for theoretical understanding of intervention evaluations. The extent to which these links are empirically supported requires systematic investigation.

Published
2019

168. Photofragment imaging and electronic spectroscopy of Al2+.

Author

Johnston, M. David, Lockwood, Schuyler P., and Metz, Ricardo B.

Subjects
*ELECTRONIC spectra, *ALUMINUM compounds, *PHOTODISSOCIATION kinetics, *STRENGTH of materials, *EXCITED state chemistry
Abstract

A combination of photodissociation spectroscopy, ion imaging, and high-level theory is employed to refine the bond strength of the aluminum dimer cation (Al2+) and elucidate the electronic structure and photodissociation dynamics between 38 500 and 42 000 cm−1. Above 40 400 cm−1, structured photodissociation is observed from an extremely anharmonic excited state, which calculations identify as the double minimum G 2Σ+u state. The photodissociation spectrum of the G 2Σ+u ← X 2Σ+g transition in Al2+ gives an average vibrational spacing of 170 cm−1 for the G 2Σ+u state and ν0 = 172 cm−1 for the ground state. Photofragment images of G 2Σ+u ← X 2Σ+g transitions indicate that once the Al (4P) + Al+ (1S) product channel is energetically accessible, it dominates the lower energy, spin-allowed pathways despite being spin-forbidden. This is explained by a proposed competition between radiative and non-radiative decay pathways from the G 2Σ+u state. The photofragment images also yield D0 (Al+–Al) = 136.6 ± 1.8 kJ/mol, the most precise measurement to date, highlighting the improved resolution achieved from imaging at near-threshold energies. Additionally, combining D0 (Al+–Al) with IE (Al) and IE (Al2) gives an improved neutral D0 (Al–Al) = 136.9 ± 1.8 kJ/mol. [ABSTRACT FROM AUTHOR]

Published
2018
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169. Photofragment imaging and electronic spectroscopy of Al2+.

Author

Johnston, M. David, Lockwood, Schuyler P., and Metz, Ricardo B.

Subjects
ELECTRONIC spectra, ALUMINUM compounds, PHOTODISSOCIATION kinetics, STRENGTH of materials, EXCITED state chemistry
Abstract

A combination of photodissociation spectroscopy, ion imaging, and high-level theory is employed to refine the bond strength of the aluminum dimer cation (Al2+) and elucidate the electronic structure and photodissociation dynamics between 38 500 and 42 000 cm−1. Above 40 400 cm−1, structured photodissociation is observed from an extremely anharmonic excited state, which calculations identify as the double minimum G 2Σ+u state. The photodissociation spectrum of the G 2Σ+u ← X 2Σ+g transition in Al2+ gives an average vibrational spacing of 170 cm−1 for the G 2Σ+u state and ν0 = 172 cm−1 for the ground state. Photofragment images of G 2Σ+u ← X 2Σ+g transitions indicate that once the Al (4P) + Al+ (1S) product channel is energetically accessible, it dominates the lower energy, spin-allowed pathways despite being spin-forbidden. This is explained by a proposed competition between radiative and non-radiative decay pathways from the G 2Σ+u state. The photofragment images also yield D0 (Al+–Al) = 136.6 ± 1.8 kJ/mol, the most precise measurement to date, highlighting the improved resolution achieved from imaging at near-threshold energies. Additionally, combining D0 (Al+–Al) with IE (Al) and IE (Al2) gives an improved neutral D0 (Al–Al) = 136.9 ± 1.8 kJ/mol. [ABSTRACT FROM AUTHOR]

Published
2018
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175. Seismicity Remotely Triggered by the Magnitude 7.3 Landers, California, Earthquake

Author

Hill, D. P., Reasenberg, P. A., Michael, A., Arabaz, W. J., Beroza, G., Brumbaugh, D., Brune, J. N., Castro, R., Davis, S., dePolo, D., Ellsworth, W. L., Gomberg, J., Harmsen, S., House, L., Jackson, S. M., Johnston, M. J. S., Jones, L., Keller, R., Malone, S., Munguia, L., Nava, S., Pechmann, J. C., Sanford, A., Simpson, R. W., Smith, R. B., Stark, M., Stickney, M., Vidal, A., Walter, S., Wong, V., and Zollweg, J.

Published
1993

176. Complete Nucleotide Sequence of Saccharomyces cerevisiae Chromosome VIII

Author

Johnston, M., Andrews, S., Brinkman, R., Cooper, J., Ding, H., Dover, J., Du, Z., Favello, A., Fulton, L., Gattung, S., Geisel, C., Kirsten, J., Kucaba, T., Hillier, L., Jier, M., Johnston, L., Langston, Y., Latreille, P., Louis, E. J., Macri, C., Mardis, E., Menezes, S., Mouser, L., Nhan, M., Rifkin, L., Riles, L., St. Peter, H., Trevaskis, E., Vaughan, K., Vignati, D., Wilcox, L., Wohldman, P., Waterston, R., Wilson, R., and Vaudin, M.

Published
1994

180. International Space Station (ISS) 3D Printer Performance and Material Characterization Methodology

Author

Bean, Q. A, Cooper, K. G, Edmunson, J. E, Johnston, M. M, and Werkheiser, M. J

Subjects
Space Processing
Abstract

In order for human exploration of the Solar System to be sustainable, manufacturing of necessary items on-demand in space or on planetary surfaces will be a requirement. As a first step towards this goal, the 3D Printing In Zero-G (3D Print) technology demonstration made the first items fabricated in space on the International Space Station. From those items, and comparable prints made on the ground, information about the microgravity effects on the printing process can be determined. Lessons learned from this technology demonstration will be applicable to other in-space manufacturing technologies, and may affect the terrestrial manufacturing industry as well. The flight samples were received at the George C. Marshall Space Flight Center on 6 April 2015. These samples will undergo a series of tests designed to not only thoroughly characterize the samples, but to identify microgravity effects manifested during printing by comparing their results to those of samples printed on the ground. Samples will be visually inspected, photographed, scanned with structured light, and analyzed with scanning electron microscopy. Selected samples will be analyzed with computed tomography; some will be assessed using ASTM standard tests. These tests will provide the information required to determine the effects of microgravity on 3D printing in microgravity.

Published
2015

181. Book review

Author

Johnston, M. R.

Published
2015

185. Review of North American Dascillidae (Coleoptera: Dascilloidea), with Descriptions of Dramatic Female Wing Reduction

Author

Johnston, M. Andrew and Gimmel, Matthew L.

Subjects
Biodiversity, Taxonomy
Abstract

Johnston, M. Andrew, Gimmel, Matthew L. (2020): Review of North American Dascillidae (Coleoptera: Dascilloidea), with Descriptions of Dramatic Female Wing Reduction. The Coleopterists Bulletin 74 (4): 731-757, DOI: 10.1649/0010-065X-74.4.731, URL: http://dx.doi.org/10.1649/0010-065x-74.4.731

Published
2020

186. Immersive captioning : developing a framework\ud for evaluating user needs

Author

Hughes, CJ, Zapata, MB, Johnston, M, and Orero, P

Abstract

This article focuses on captioning for immersive\ud environments and the research aims to identify how to display\ud them for an optimal viewing experience. This work began four\ud years ago with some partial findings. This second stage of\ud research, built from the lessons learnt, focuses on the design\ud requirements cornerstone: prototyping. A tool has been\ud developed towards quick and realistic prototyping and testing.\ud The framework integrates methods used in existing solutions.\ud Given how easy it is to contrast and compare, the need to further\ud the first framework was obvious. A second improved solution\ud was developed, almost as a showcase on how ideas can quickly\ud be implemented for user testing. After an overview on captions\ud in immersive environments, the article describes its\ud implementation, based on web technologies opening for any\ud device with a web browser. This includes desktop computers,\ud mobile devices and head mounted displays. The article finishes\ud with a description of the new caption modes leading to improved\ud methods, hoping to be a useful tool towards testing and\ud standardisation.

Published
2020

193. A Randomised Patient-Focused Trial of the Achieving Self-Directed Integrated Cancer Aftercare (ASICA) Intervention for Detection of Recurrent and Second Primary Melanoma: Effect on Psychological Well-Being and Quality of Life

Author

Murchie, P, primary, Constable, L, additional, Hall, S, additional, Brant, W, additional, Allan, JL, additional, Johnston, M, additional, Masthoff, J, additional, Lee, AJ, additional, Treweek, Sarah, additional, Ayansina, D, additional, Proby, Charlotte M., additional, Rahman, K, additional, Walter, FM, additional, Burrows, N, additional, Durrani, A, additional, and Maclennan, G, additional

Published
2021
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196. Faecal calprotectin helps determine the need for post-operative colonoscopy in crohnʼs disease. prospective longitudinal endoscopic validation. Results from the POCER study

Author

WRIGHT, E K, DE CRUZ, P, KAMM, M A, HAMILTON, A L, RITCHIE, K, KREJANY, S, LEACH, S T, KEENAN, J I, GORELIK, A, LIEW, D, PRIDEAUX, L, LAWRANCE, I C, ANDREWS, J M, BAMPTON, P A, SPARROW, M, FLORIN, T H, GIBSON, P R, DEBINSKI, H, MACRAE, F A, LEONG, R W, KRONBORG, I, RADFORD-SMITH, G, SELBY, W, JOHNSTON, M J, WOODS, R, ELLIOTT, P R, BELL, S, BROWN, S J, CONNELL, W, DAY, A S, GEARRY, R B, and DESMOND, P V

Published
2013

197. Smoking is the key risk factor that doubles the risk of postoperative recurrence of Crohnʼs disease despite preventive drug treatment. Results from the POCER study

Author

DE CRUZ, P, KAMM, M, HAMILTON, A, RITCHIE, K, KREJANY, S, GORELIK, A, LIEW, D, PRIDEAUX, L, LAWRANCE, I, ANDREWS, J, BAMPTON, P, SPARROW, M, FLORIN, T, GIBSON, P, DEBINSKI, H, GEARRY, R, MACRAE, F, LEONG, R, KRONBORG, I, RADFORD-SMITH, G, SELBY, W, JOHNSTON, M, WOODS, R, ELLIOTT, R, BELL, S, BROWN, S, CONNELL, W, and DESMOND, P

Published
2013

198. Optimising postoperative Crohnʼs disease management: Best drug therapy alone versus endoscopic monitoring with treatment step-up. The pocer study

Author

DE CRUZ, P, KAMM, M, HAMILTON, A, RITCHIE, K, KREJANY, S, GORELIK, A, LIEW, D, PRIDEAUX, L, LAWRANCE, I, ANDREWS, J, BAMPTON, P, SPARROW, M, FLORIN, T, GIBSON, P, DEBINSKI, H, GEARRY, R, MACRAE, F, LEONG, R, KRONBORG, I, RADFORD-SMITH, G, SELBY, W, JOHNSTON, M, WOODS, R, ELLIOTT, R, BELL, S, BROWN, S, CONNELL, W, and DESMOND, P

Published
2013

199. Strategic timing of anti-TNF therapy in postoperative Crohnʼs disease: Comparison of routine use immediately postoperatively with selective use after demonstrated recurrence at 6 month endoscopy. Results from POCER

Author

DE CRUZ, P, KAMM, M, HAMILTON, A, RITCHIE, K, KREJANY, S, GORELIK, A, LIEW, D, PRIDEAUX, L, LAWRANCE, I, ANDREWS, J, BAMPTON, P, SPARROW, M, FLORIN, T, GIBSON, P, DEBINSKI, H, GEARRY, R, MACRAE, F, LEONG, R, KRONBORG, I, RADFORD-SMITH, G, SELBY, W, JOHNSTON, M, WOODS, R, ELLIOTT, R, BELL, S, BROWN, S, CONNELL, W, and DESMOND, P

Published
2013

200. Impaired lymphatic cerebrospinal fluid absorption in a rat model of kaolin-induced communicating hydrocephalus

Author

Nagra, G., Li, J., McAllister, J.P., II, Miller, J., Wagshul, M., and Johnston, M.

Subjects
Hydrocephalus -- Physiological aspects, Cerebrospinal fluid -- Properties, Rats -- Diseases, Rats -- Physiological aspects, Rattus -- Diseases, Rattus -- Physiological aspects, Intracranial pressure -- Measurement, Neurophysiology -- Research, Biological sciences
Abstract

It has been assumed that the pathogenesis of hydrocephalus includes a cerebrospinal fluid (CSF) absorption deficit. Because a significant portion of CSF absorption occurs into extracranial lymphatics located in the olfactory turbinates, the purpose of this study was to determine whether CSF transport was compromised at this location in a kaolin-induced communicating (extraventricular) hydrocephalus model in rats. Under 1-3% halothane anesthesia, kaolin (n = 10) or saline (n = 9) was introduced into the basal cisterns of Sprague-Dawley rats, and the development of hydrocephalus was assessed 1 wk later using MRI. After injection of human serum albumin ([sup.125]I-HSA) into a lateral ventricle, the tracer enrichment in the olfactory turbinates 30 min postinjection provided an estimate of CSF transport through the cribriform plate into nasal lymphatics. Lateral ventricular volumes in the kaolin group (0.073 [+ or -] 0.014 ml) were significantly greater than those in the saline-injected animals (0.016 [+ or -] 0.001 ml; P = 0.0014). The CSF tracer enrichment in the olfactory turbinates (expressed as percent injected/g tissue) in the kaolin rats averaged 0.99 [+ or -] 0.39 and was significantly lower than that measured in the saline controls (5.86 [+ or -] 0.32; P < 0.00001). The largest degree of ventriculomegaly was associated with the lowest levels of lymphatic CSF uptake with lateral ventricular expansion occurring only when almost all of the lymphatic CSF transport capacity had been compromised. We conclude that lymphatic CSF absorption is impaired in a kaolin-communicating hydrocephalus model and that the degree of this impediment may contribute to the severity of the induced disease. extraventricular hydrocephalus; ventriculomegaly; cribriform plate; olfactory turbinates; arachnoid villi and granulations; lymph; intracranial pressure

Published
2008

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