793 research outputs found
Correlation tracking study for meter-class solar telescope on space shuttle
The theory and expected performance level of correlation trackers used to control the pointing of a solar telescope in space using white light granulation as a target were studied. Three specific trackers were modeled and their performance levels predicted for telescopes of various apertures. The performance of the computer model trackers on computer enhanced granulation photographs was evaluated. Parametric equations for predicting tracker performance are presented
All the colours of the rainbow.
Our perception of colour has always been a source of fascination, so it's little wonder that studies of the phenomenon date back hundreds of years. What, though, can modern scientists learn from medieval literature — and how do we go about it
All the colours of the rainbow
Our perception of colour has always been a source of fascination, so it's little wonder that studies of the phenomenon date back hundreds of years. What, though, can modern scientists learn from medieval literature — and how do we go about it
Automated Data Management Information System (ADMIS)
ADMIS stores and controls data and documents associated with manned space flight effort. System contains all data oriented toward a specific document; it is primary source of reports generated by the system. Each group of records is composed of one document record, one distribution record for each recipient of the document, and one summary record
The independent group looks at London's west end
In the early 1950s, British culture was dominated by welfare-state visions of urban reconstruction. These projections of a stable civic society were premised on a particular way of looking at and reading the metropolitan environment. At odds with this project, the Independent Group's discussions and collaborative work developed an alternative urban semiology, which found the city to be already rich in visual resources for fashioning a more profound form of social democracy. Soon, this critical engagement would develop in different directions, represented here by Lawrence Alloway's commentary on Piccadilly Circus in his essay 'City Notes' and the London footage inserted by John McHale into his film for the Smithsons' Berlin Hauptstadt project (both 1959). By the end of the 1950s, members of the erstwhile Independent Group had produced two contrasting critical accounts of how the metropolitan centre should be looked at, which challenged the strictures of post-war reconstruction in distinct and conflicting ways. © The Author(s), 2013
Self-Compassion in Chinese Young Adults: Its Measurement and Measurement Construct
This is the final version. Available on open access from SAGE Publications via the DOI in this recordAvailability of Data and Analysis Syntax: All data and data analysis syntax are available upon request from the authors.OBJECTIVES: Self-compassion is the ability to be kind to oneself in adversity. This multidimensional construct is typically assessed by the Self-Compassion Scale (SCS). In Chinese samples, there have been inconsistent psychometric findings that impede cross-cultural research. This study aimed to explore the factor structure of the Chinese version (SCS-C). METHODS: Two samples of young Chinese adults were recruited (Sample 1, N = 465, 141 men, Mean age [Mage] = 20.26; Sample 2, N = 392, 71 men; Mage = 18.97). Confirmatory factor analyses and exploratory structural equation modeling (ESEM) were used to examine previously reported four- and six-factor structures of SCS-C. RESULTS: Although ESEM supported the six-factor structure when a problematic item was omitted, we found stronger evidence for a novel four-factor structure of the SCS-C revealed with self-kindness, common humanity, mindfulness, and uncompassionate self-responding. This suggests that Chinese individuals have a different understanding of the negative components of the original self-compassion definition, which was based on the United States and other mostly Western samples. Omega coefficients of the bifactor models suggested that using the SCS total score in Chinese samples is inappropriate. However, high factor determinacy and construct replicability indicated that the general factor of SCS-C could be used in a structural equation modeling context for both four-factor and six-factor structures. CONCLUSIONS: When using the existing SCS-C in path models, researchers should use a latent variable approach and establish the measurement construct rather than sum scores of the scale or subscales without checking the factor structure in future empirical studies. Also, the SCS-C needs to be revised, and we proposed directions forward for future research.University of Exete
Rebuilding terrestrial ecosystems after the end-Devonian mass extinction: insights from the TW:eed Project
The TW:eed (Tetrapod World: early evolution and diversification) project is a
major research initiative that will generate a coherent picture of the biotic,
environmental and geological conditions of the 15-20 million years recovery period
following the major extinction event at the end-Devonian that was a major turning point
in terrestrial evolution. A paucity of terrestrial invertebrates and few fossils of early
tetrapods have been found in post-Devonian successions from the immediate aftermath
(Romer’s Gap) and yet, during a relatively brief time period in the Early Carboniferous,
fully terrestrial vertebrates evolved, terrestrial arthropods radiated, ray-finned fishes took
over from lobe-finned forms and plant groups diversified. Several new localities in
Carboniferous successions in southern Scotland and northern England are providing
completely new insights into this pivotal period for the evolution of life on land.
Significant new tetrapod material is helping to populate Romer’s Gap. Localities are also
yielding a diverse fauna of fish (gyracanthids, lungfish, rhizodonts and
actinopterygians), invertebrates (malacostracans, eurypterids, ostracods, scorpions and
myriapods) and plants. The fossil localities are within the Ballagan Formation, a
distinctive unit comprising mudstones with interbedded sandstones, palaeosols and thin
beds of dolomitic “cementstone”. The sediments were deposited on an extensive low
relief, muddy, vegetated floodplain that was traversed by numerous river systems.
Periodically the river-derived floods submerged the floodplains generating extensive
shallow freshwater lakes. The presence of gypsum and anhydrite indicates that there
were occasional marine transgressions across a marginal coastal plain. So far, most of
the fossils have been found towards the top of the Ballagan Formation, but a coastal
exposure of the entire formation provides a unique opportunity to search for fossils
across a time interval of about 15 million years at the base of the Carboniferous.
In addition to the detailed analysis of key outcrops, a drilling program in the
Tweed Basin is in the process of acquiring 500 m of continuous core through these
earliest Carboniferous successions. A tight stratigraphic framework for tetrapod
localities across the region will be generated by integrating the sedimentological
(lithostratigraphy), micropalaeontological (biostratigraphy), chemostratigraphical (carbon
and oxygen stable isotopes) and petrophysical data from the core and outcrops. The
borehole will provide the high-resolution datasets required to investigate the local, and
potentially, global palaeoclimate and its evolution through this time interval. This
multifaceted project is a unique opportunity to examine the progression, causes and
context of the rebuilding of an ecosystem following a major extinction
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