166 research outputs found
Constraints on Martian Ancient Magmatic Processes Using Mineral Chemistry of Sedimentary Rocks in Gale Crater, Mars
If Mars has been assumed to be mostly basaltic for a long time, a series of recent discoveries have challenged this simplistic view. Orbital data indicated feldspar-rich rocks in Noachian terrains, likely supporting ancient evolved magmatism. The first indurated regolithic martian meteorite breccia NWA 7034, dated at 4.43 Gyr, contain several leucocratic felsic clasts identified as monzonitic and trachyandesitic, containing feldspars including K-spars and Na-rich plagioclases, pyroxenes, ilmenites and apatites. These clasts have been interpreted as the result of crystallization of a large impact pond. The Mars Science Laboratory rover (Curiosity), travelling within sedimentary bedrock on the floor of the Gale impact crater, discovered feldspar cumulates and a trachyandesite suggesting fractional crystallization of a basaltic melt. In addition, in the Bradbury group of fluvio-deltaic rocks (observed during the 1st 750 sols), sedimentary rocks are mostly comprised of secondary phases and detrital igneous minerals like feldspar, and pyroxene that are thought to come from Noachian-aged magmatic sources, although no definite origin and igneous processes have been inferred
The Role of Diagenesis at Vera Rubin Ridge in Gale Crater, Mars, and the Chemostratigraphy of the Murray Formation as Observed by the Chemcam Instrument
The Mars Science Laboratory (MSL) Curiosity rover explored Vera Rubin ridge (VRR) in Gale crater, Mars, for almost 500 sols (Mars days) between arriving at the ridge on sol 1809 of the mission in September 2017 and leaving it on sol 2302 upon entering the Glen Torridon area south of the ridge. VRR is a topographic ridge on the central mound, Aeolis Mons (Mt. Sharp), in Gale crater that displays a strong hematite spectral signature from orbit. In-situ observations on the ridge led to the recognition that the ridge-forming rocks belong to the Murray formation, the lowermost exposed stratigraphic unit of the Mt. Sharp group, that was first encountered at the Pahrump Hills location. Including VRR rocks, the Murray formation, interpreted to be primarily deposited in an ancient lacustrine environment in Gale crater, is more than 300 m thick. VRR itself is composed of two stratigraphic members within the Murray formation, the Pettegrove Point member overlain by the Jura member. The Pettegrove Point member overlies the Blunts Point member of the Murray formation. Areas of gray coloration are observed in the Jura member predominantly, but also in the Pettegrove Point member. Generally, gray areas are found in local topographic depressions, but contacts between red and gray rocks crosscut stratigraphy. Additionally, cm-scale dark concretions with very high iron-content are commonly observed in gray rocks, typically surrounded by a lighttoned zone that is conversely depleted in iron. A key goal for the VRR campaign was to characterize geochemical variations in the ridge-forming rocks to investigate the role of primary and diagenetic controls on the geochemistry and morphology of VRR. Here, we present observations by the ChemCam instrument on VRR and compare these to the full Murray formation chemostratigraphy. This work was recently submitted to a special issue of JGRPlanets that detail the full VRR campaign
Voice interfaces in everyday life
Voice User Interfaces (VUIs) are becoming ubiquitously available, being embedded both into everyday mobility via smartphones, and into the life of the home via âassistantâ devices. Yet, exactly how users of such devices practically thread that use into their everyday social interactions remains underexplored. By collecting and studying audio data from month-long deployments of the Amazon Echo in participantsâ homesâinformed by ethnomethodology and conversation analysisâour study documents the methodical practices of VUI users, and how that use is accomplished in the complex social life of the home. Data we present shows how the device is made accountable to and embedded into conversational settings like family dinners where various simultaneous activities are being achieved. We discuss how the VUI is finely coordinated with the sequential organisation of talk. Finally, we locate implications for the accountability of VUI interaction, request and response design, and raise conceptual challenges to the notion of designing âconversationalâ interfaces
Models and metaphors: complexity theory and through-life management in the built environment
Complexity thinking may have both modelling and metaphorical applications in the through-life management of the built environment. These two distinct approaches are examined and compared. In the first instance, some of the sources of complexity in the design, construction and maintenance of the built environment are identified. The metaphorical use of complexity in management thinking and its application in the built environment are briefly examined. This is followed by an exploration of modelling techniques relevant to built environment concerns. Non-linear and complex mathematical techniques such as fuzzy logic, cellular automata and attractors, may be applicable to their analysis. Existing software tools are identified and examples of successful built environment applications of complexity modelling are given. Some issues that arise include the definition of phenomena in a mathematically usable way, the functionality of available software and the possibility of going beyond representational modelling. Further questions arising from the application of complexity thinking are discussed, including the possibilities for confusion that arise from the use of metaphor. The metaphor of a 'commentary machine' is suggested as a possible way forward and it is suggested that an appropriate linguistic analysis can in certain situations reduce perceived complexity
Effect and process evaluation of a kindergarten-based, family-involved cluster randomised controlled trial in six European countries on four- to six-year-old children's steps per day: The ToyBox-study
Background: The ToyBox-intervention is a theory- and evidence-based intervention delivered in kindergartens to improve four- to six-year-old children''s energy balance-related behaviours and prevent obesity. The current study aimed to (1) examine the effect of the ToyBox-intervention on increasing European four- to six-year-old children'' steps per day, and (2) examine if a higher process evaluation score from teachers and parents was related to a more favourable effect on steps per day. Methods: A sample of 2438 four- to six-year-old children (51.9% boys, mean age 4.75±0.43years) from 6 European countries (Belgium, Bulgaria, Germany, Greece, Poland and Spain) wore a motion sensor (pedometer or accelerometer) for a minimum of two weekdays and one weekend day both at baseline and follow-up to objectively measure their steps per day. Kindergarten teachers implemented the physical activity component of the ToyBox-intervention for 6 weeks in total, with a focus on (1) environmental changes in the classroom, (2) the child performing the actual behaviour and (3) classroom activities. Children''s parents received newsletters, tip cards and posters. To assess intervention effects, multilevel repeated measures analyses were conducted for the total sample and the six intervention countries separately. In addition, process evaluation questionnaires were used to calculate a total process evaluation score (with implementation and satisfaction as a part of the overall score) for teachers and parents which was then linked with the physical activity outcomes. Results: No significant intervention effects on four- to six-year-old children'' steps per weekday, steps per weekend day and steps per average day were found, both in the total sample and in the country-specific samples (all p>0.05). In general, the intervention effects on steps per day were least favourable in four- to six-year-old children with a low teachers process evaluation score and most favourable in four- to six-year-old children with a high teachers process evaluation score. No differences in intervention effects were found for a low, medium or high parents'' process evaluation score. Conclusion: The physical activity component of the ToyBox-intervention had no overall effect on four- to six-year-old children'' steps per day. However, the process evaluation scores showed that kindergarten teachers that implemented the physical activity component of the ToyBox-intervention as planned and were satisfied with the physical activity component led to favourable effects on children''s steps per day. Strategies to motivate, actively involve and engage the kindergarten teachers and parents/caregivers are needed to induce larger effects
Differences in energy balance-related behaviours in European preschool children: The ToyBox-study
Background: The aim of the current study was to compare levels of energy balance-related behaviours (physical activity, sedentary behaviour, and dietary behaviours (more specifically water consumption, sugar-sweetened beverage consumption and unhealthy snacking)) in four- to six-year-old preschoolers from six European countries (Belgium, Bulgaria, Germany, Greece, Poland, and Spain) within the ToyBox cross-sectional study. Methods: A sample of 4,045 preschoolers (4.77 ± 0.43 years; 52.2% boys) had valid physical activity data (steps per day), parents of 8,117 preschoolers (4.78 ± 0.46 years; 53.0% boys) completed a parental questionnaire with questions on sedentary behaviours (television viewing, computer use, and quiet play), and parents of 7,244 preschoolers (4.77 ± 0.44 years; 52.0% boys) completed a food frequency questionnaire with questions on water consumption, sugar-sweetened beverage consumption and unhealthy snacking. Results: The highest levels of physical activity were found in Spain (12,669 steps/day on weekdays), while the lowest levels were found in Bulgaria and Greece (9,777 and 9,656 steps/day on weekdays, respectively). German preschoolers spent the least amount of time in television viewing (43.3 min/day on weekdays), while Greek preschoolers spent the most time in television viewing (88.5 min/day on weekdays). A considerable amount of time was spent in quiet play in all countries, with the highest levels in Poland (104.9 min/day on weekdays), and the lowest levels in Spain (60.4 min/day on weekdays). Belgian, German, and Polish preschoolers had the lowest intakes of water and the highest intakes of sugar-sweetened beverages. The intake of snacks was the highest in Belgian preschoolers (73.1 g/day) and the lowest in Greek preschoolers (53.3 g/day). Conclusions: Across six European countries, differences in preschoolers'' energy balance-related behaviours were found. Future interventions should target European preschoolers '' energy balance- related behaviours simultaneously, but should apply country-specific adaptations
Ventriculocisternostomia de Torkildsen no tratamento do hidrocefalo nĂŁo comunicante: resultados em 67 casos
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