30 research outputs found
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
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United States Geological Survey Report TEI-321
From introduction: This report contains the results of a detailed geological and uranium deposits study made of the Monument Valley
Choroidal osteoma: evidence of progression and decalcification over 20 years
Choroidal osteoma is a rare, benign, ossifying tumour of the choroid of unknown aetiology. In contrast to other types of intraocular ossification, choroidal osteoma is found typically in young healthy females in the second or third decades of life with no history of systemic or ocular disease. Choroidal osteoma is a deep, pale yellow lesion with distinct geographic borders at the juxtapapillary or macular region, with branching 'spider' vessels on the surface of the tumour. These features should help differentiate choroidal osteoma from other types of intraocular tumour and the diagnosis can be confirmed with ultrasonography and computerised tomography. Here we report an initially unilateral case of choroidal osteoma, which decalcified over 20 years but during the same period the fellow eye also developed a choroidal osteoma to become a bilateral case. Despite the benign nature of the tumour, vision may be compromised by gradual atrophy of the overlying retina, serous retinal detachment, accumulation of sub-retinal fluid and sub-retinal haemorrhage associated with choroidal neovascularisation. Frequent examinations are recommended for patients with choroidal osteoma, for early detection of a subretinal neovascular membrane and potential treatment with laser photocoagulation
Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study:associations of maternal A1C and glucose with pregnancy outcomes
OBJECTIVE-To compare associations of maternal glucose and MC with adverse outcomes in the multinational Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study and determine, based on those comparisons, if A1C measurement can provide an alternative to an oral glucose tolerance test (OGTT) in pregnant women
Hyperglycemia and adverse pregnancy outcome study:Neonatal glycemia
OBJECTIVE: The goal was to describe the temporal pattern of neonatal plasma glucose levels and associations with maternal glucose levels, cord serum C-peptide levels, and neonatal size and adiposity
Peaks of Identity in Colorado’s San Juan Mountains
The glaciated ranges of southwestern Colorado constituting the San Juan Mountains are culturally significant to residents and visitors. As certain mountains are imbued with meaning, they become "peaks of identity," tangible and towering symbolic landscapes representing a distinctive set of community and cultural ideals. This paper explores the symbols and themes of San Juan peaks of identity, with a focus on the mountain amenity town of Lake City and nearby Uncompahgre Peak. Uncompahgre's icon dominates mountain representations in Lake City and instantly identifies the community; its symbolism embodies aesthetics of form and elevation and the sanctity of hallowed ground. Mountain symbolism in the San Juans is mainly projected through land use and the display of icons and names on signs and government seals. Although the San Juans are sacred to the Utes and Navajos and represent a rich mining heritage, they also symbolize idealized natural scenery, landmarks of home, recreation opportunities, and spiritual renewal. Many San Juan communities identify with mountains in a generic sense, but this article focuses on the traits, variability, and depth of meaning of the mountains that are landscape signatures of community identity
Legacy Effects in Material Flux: Structural Catchment Changes Predate Long-Term Studies
Legacy effects of past land use and disturbance are increasingly recognized, yet consistent definitions of and criteria for defining them do not exist. To address this gap in biological- and ecosystem-assessment frameworks, we propose a general metric for evaluating potential legacy effects, which are computed by normalizing altered system function persistence with duration of disturbance. We also propose two distinct legacy-effect categories: signal effects from lags in transport and structural effects from physical landscape changes. Using flux records for water, sediment, nitrogen, and carbon from long-term study sites in the eastern United States from 1500 to 2000, we identify gaps in our understanding of legacy effects and reveal that changes in basin sediment dynamics precede instrumented records. These sediment dynamics are not generally incorporated into interpretations of contemporary records, although their potential legacy effects are substantial. The identification of legacy effects may prove to be a fundamental component of landscape management and effective conservation and restoration practice.National Science Foundation (U.S.) (Cooperative Agreement DEB-0236154)National Science Foundation (U.S.). Long-Term Ecological Research Network (Grant NSF-OCE-0423565