14,421 research outputs found

    The B-ring's surface mass density from hidden density waves: Less than meets the eye?

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    Saturn's B ring is the most opaque ring in our solar system, but many of its fundamental parameters, including its total mass, are not well constrained. Spiral density waves generated by mean-motion resonances with Saturn's moons provide some of the best constraints on the rings' mass density, but detecting and quantifying such waves in the B ring has been challenging because of this ring's high opacity and abundant fine-scale structure. Using a wavelet-based analyses of 17 occultations of the star gamma Crucis observed by the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft, we are able to examine five density waves in the B ring. Two of these waves are generated by the Janus 2:1 and Mimas 5:2 Inner Lindblad Resonances at 96,427 km and 101,311 km from Saturn's center, respectively. Both of these waves can be detected in individual occultation profiles, but the multi-profile wavelet analysis reveals unexpected variations in the pattern speed of the Janus 2:1 wave that might arise from the periodic changes in Janus' orbit. The other three wave signatures are associated with the Janus 3:2, Enceladus 3:1 and Pandora 3:2 Inner Lindblad Resonances at 115,959 km, 115,207 km and 108,546 km. These waves are not visible in individual profiles, but structures with the correct pattern speeds can be detected in appropriately phase-corrected average wavelets. Estimates of the ring's surface mass density derived from these five waves fall between 40 and 140 g/cm^2, even though the ring's optical depth in these regions ranges from 1.5 to almost 5. This suggests that the total mass of the B ring is most likely between one-third and two-thirds the mass of Saturn's moon Mimas.Comment: 40 Pages, 21 Figures, Accepted for publication in Icarus, a few typos fixe

    Shaping the future for primary care education and training project. Integrated health and social care: the perspectives of people using services: a mixed methods analysis

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    The aim of this study was to explore service users' perspectives concerning integrated health & social care, and to identify the perceived strengths and weaknesses associated with the current workforce and services provided. The findings will be used to inform the education and training of the health and social care workforce in the North West of Englan

    IMPACTS OF THE NORTHEAST INTERSTATE DAIRY COMPACT ON NEW ENGLAND MILK SUPPLY

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    A two-equation random coefficients model and two estimates of milk prices in the absence of the Northeast Interstate Dairy Compact (Compact) are used to estimate the impact of minimum price regulation for fluid milk products on milk production in the New England states. Estimated responses to price enhancement differed by state for cow numbers, but parameters for milk per cow were not significantly different among states. The amount of increase in milk production attributed to the Compact is estimated at 45 million pounds (about 1% of production) during the first year of minimum price regulation, primarily due to increased milk per cow.Demand and Price Analysis,

    Play-based pedagogy under threat? A small-scale study of teachers’ and pupils’ perceptions of pedagogical discontinuity in the transition to primary school

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    This study explored teachers’ and pupils’ perceptions of pedagogical discontinuity in the transition from Reception to Year 1. Data were collected through interviews with one Early Years Foundation Stage (EYFS) and one Year 1 teacher in the same setting. A questionnaire distributed to Year 1 children (n = 23) provided supplementary data. Findings revealed that teachers and pupils were aware of pedagogical discontinuity in the transition from EYFS to Year 1. Teachers attributed pedagogical discontinuity to the constraints of the National Curriculum. Pressures to ensure children are ‘school ready’ also have implications for bridging pedagogical discontinuity through play

    Synthesis and assembly of mitochondrial proteins

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