702 research outputs found

    Space station functional relationships analysis

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    A systems engineering process is developed to assist Space Station designers to understand the underlying operational system of the facility so that it can be physically arranged and configured to support crew productivity. The study analyzes the operational system proposed for the Space Station in terms of mission functions, crew activities, and functional relationships in order to develop a quantitative model for evaluation of interior layouts, configuration, and traffic analysis for any Station configuration. Development of the model involved identification of crew functions, required support equipment, criteria of assessing functional relationships, and tools for analyzing functional relationship matrices, as well as analyses of crew transition frequency, sequential dependencies, support equipment requirements, potential for noise interference, need for privacy, and overall compatability of functions. The model can be used for analyzing crew functions for the Initial Operating Capability of the Station and for detecting relationships among these functions. Note: This process (FRA) was used during Phase B design studies to test optional layouts of the Space Station habitat module. The process is now being automated as a computer model for use in layout testing of the Space Station laboratory modules during Phase C

    Valuing life detection missions

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    Recent discoveries imply that Early Mars was habitable for life-as-we-know-it; that Enceladus might be habitable; and that many stars have Earth-sized exoplanets whose insolation favors surface liquid water. These exciting discoveries make it more likely that spacecraft now under construction - Mars 2020, ExoMars rover, JWST, Europa Clipper - will find habitable, or formerly habitable, environments. Did these environments see life? Given finite resources (\$10bn/decade for the US ), how could we best test the hypothesis of a second origin of life? Here, we first state the case for and against flying life detection missions soon. Next, we assume that life detection missions will happen soon, and propose a framework for comparing the value of different life detection missions: Scientific value = (Reach x grasp x certainty x payoff) / \$ After discussing each term in this framework, we conclude that scientific value is maximized if life detection missions are flown as hypothesis tests. With hypothesis testing, even a nondetection is scientifically valuable.Comment: Accepted by "Astrobiology.

    Faces and Viewing Behavior: An Exploratory Investigation

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    User experience is becoming increasingly important in gaining a competitive advantage in the marketplace. One way to improve user experience is by including images of faces. People are drawn to faces because paying attention to faces has played a significant role in human evolution. Hence, areas on a web page that typically receive less attention from users, such as the right side or below the fold, may benefit from the inclusion of images of faces. Although faces may be useful in attracting attention to particular places on a web page, they may also distract attention from key information. To test this possibility, we conducted two eye tracking studies in which images of faces were placed on areas of a web page that are shown to receive less attention. The results indicated that faces did not increase the number of people who viewed the areas where the faces were located, but that faces affected fixation patterns on these areas. Our results also showed that faces located above the fold of the web page negatively affected the performance of those who were completing tasks

    Fluid-Assisted Strain Localization in Quartz at the Brittle/Ductile Transition

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    A mylonitic quartzite with conjugate and synthetic shear bands was investigated by Electron Backscatter Diffraction and optical microscopy to obtain insights on recrystallization mechanisms and strain localization in quartz at plastic to semibrittle conditions close to the brittle-ductile transition. The mylonitic quartzite deformed during late Miocene thrusting coeval with contact metamorphism in the high-strain domains of the Calamita Schists (Elba Island, Italy). Mylonitic deformation occurred from amphibolite to lower greenschist facies conditions during cooling of the aureole. Dynamic recrystallization, dominated by the activity of dislocation creep by prism slip, produced recrystallized quartz layers mantling relic large quartz porphyroclasts. Under decreasing temperature and fluid-rich conditions, quartz porphyroclasts acted as relatively rigid bodies and fractured along synthetic and conjugate C′ shear bands. Shear bands developed along kinematically favored orientations, just locally assisted by weak crystallographic planes in quartz. Fracturing along shear bands was assisted by cataclasis and fluid infiltration enhancing fracture propagation and healing by recrystallization and authigenesis of new quartz and phyllosilicate grains. The process enhanced the propagation of and strain localization in shear bands, with the development of bands of weak phyllosilicates. Furthermore, we observed the development of a c axis preferred orientation (CPO) related to dissolution and precipitation of new grains with their c axis oriented parallel to shear bands. This study highlights the importance of the interplay between brittle and crystal-plastic processes and fluid ingress in the semibrittle regime to understand deformation partitioning and strain localization

    A novel paradigm for attributing the diagnosis of CF disease

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    The ABCD of usability testing

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    We introduce a methodology for tracking and auditing feedback, errors and suggestions for software packages. This short paper describes how we innovate on the evaluation mechanism, introducing an (Antecedent, Barrier, Consequence and Development) ABCD form, embedded within an eParticipation platform to enable end users to easily report on any usability issues. This methodology will be utilised to improve the STEP cloud eParticipation platform (part of the current STEP Horizon2020 project http://step4youth.eu. The platform is currently being piloted in real life contexts, with the participation of public authorities that are integrating the eParticipation platform into their regular decision-making practices. The project is involving young people, through engagement and motivation strategies and giving them a voice in Environmental decision making at the local level. The pilot evaluation aims to demonstrate how open engagement needs to be embedded within public sector processes and the usability methodology reported here will help to identify the key barriers for wide scale deployment of the platform

    Where Do We Go From Here? The Need for Genetic Referrals in Patients who are Deaf or Hard of Hearing: Findings from a Regional Survey

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    Purpose: The purpose of this study was to assess primary health care providers’ knowledge and use of genetic services for children whose hearing screening indicates they may be deaf/hard of hearing (D/HH) and identify areas in which health care providers can be supported to increase family education and referral of families for genetic consultation. Methodology: A survey was developed on current practices, knowledge, and perceived beliefs regarding genetic education and referrals for deafness. The surveys were distributed to pediatricians, family medicine physicians, nurse practitioners, and physician assistants in DC, DE, MD, NJ, NY, PA, VA, and WV. Results: Among 266 respondents, 80% were uninformed about Early Hearing Detection Intervention (EHDI) 1-3-6 guidelines prior to taking the survey. Approximately 55% were not confident about the genetic causes of deafness, 44% rarely consulted genetics professionals, 41% had not referred families to genetics, and 37% were not confident about the importance of genetic referrals. Conclusions: Integrated, targeted, and user-friendly genetics education strategies in the existing EHDI framework are needed to ensure adequate awareness and delivery of genetics services for D/HH children

    Dioxinlike properties of a trichloroethylene combustion-generated aerosol.

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    Conventional chemical analyses of incineration by-products identify compounds of known toxicity but often fail to indicate the presence of other chemicals that may pose health risks. In a previous report, extracts from soot aerosols formed during incomplete combustion of trichloroethylene (TCE) and pyrolysis of plastics exhibited a dioxinlike response when subjected to a keratinocyte assay. To verify this dioxinlike effect, the complete extract, its polar and nonpolar fractions, some containing primarily halogenated aromatic hydrocarbons, were evaluated for toxicity using an embryo assay, for antiestrogenicity using primary liver cell cultures, and for the ability to transform the aryl hydrocarbon receptor into its DNA binding form using liver cytosol in a gel retardation assay. Each of these assays detect dioxinlike effects. Medaka (Oryzias latipes) embryos and primary liver cell cultures of rainbow trout (Oncorhynchus mykiss) were exposed to concentrations of extract ranging from 0.05 to 45 micrograms/l. Cardiotoxicity with pericardial, yolk sac, and adjacent peritoneal edema occurred after exposure of embryos to concentrations of 7 micrograms/l or greater. These same exposure levels were associated with abnormal embryo development and, at the higher concentrations, death. Some of the fractions were toxic but none was as toxic as the whole extract. In liver cells, total cellular protein and cellular lactate dehydrogenase activity were not altered by in vitro exposure to whole extract (0.05-25 micrograms/l). However, induction of cytochrome P4501A1 protein and ethoxyresorufin O-deethylase activity occurred. In the presence of whole extract, estradiol-dependent vitellogenin synthesis was reduced. Of the fractions, only fraction 1 (nonpolar) showed a similar trend, although vitellogenin synthesis inhibition was not significant. The soot extract and fractions bound to the Ah receptor and showed a significantly positive result in the gel retardation/DNA binding test. Chemical analyses using GC-MS with detection limits for 2,3,7,8-tetrachlorodibenzo-p-dioxin and dibenzofuran in the picomole range did not show presence of these compounds. Our results indicate that other chemicals associated with TCE combustion and not originally targeted for analysis may also pose health risks through dioxinlike mechanisms
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