408 research outputs found
The partnership: Space shuttle, space science, and space station
An overview of the NASA Space Station Program functions, design, and planned implementation is presented. The discussed functions for the permanently manned space facility include: (1) development of new technologies and related commercial products; (2) observations of the Earth and the universe; (3) provision of service facilities for resupply, maintenance, upgrade and repair of payloads and spacecraft; (4) provision of a transportation node for stationing, processing and dispatching payloads and vehicles; (5) provision of manufacturing and assembly facilities; (6) provision of a storage depot for parts and payloads; and (7) provision of a staging base for future space endeavors. The fundamental concept for the Space Station, as given, is that it be designed, operated, and evolved in response to a broad variety of scientific, technological, and commercial user interests. The Space Shuttle's role as the principal transportation system for the construction and maintenance of the Space Station and the servicing and support of the station crew is also discussed
Alternative Datasets for Identification of Earth Science Events and Data
Alternative, or non-traditional, data sources can be used to generate datasets which can in turn be analyzed for temporal, spatial and climatological patterns. Events and case studies inferred from the analysis of these patterns can be used by the remote sensing community to more effectively search for Earth observation data. In this paper, we present a new alternative Earth science dataset created from the National Weather Services Area Forecast Discussion (AFD) documents. We then present an exploratory methodology for identifying interesting climatological patterns within the AFD data and a corresponding motivating example as to how these data and patterns can be used to search for relevant events or case studies
Applications of stable water and carbon isotopes in watershed research: Weathering, carbon cycling, and water balances
Research on rivers has traditionally involved concentration and flux measurements to better understand
weathering, transport and cycling of materials from land to ocean. As a relatively new tool, stable isotope
measurements complement this type of research by providing an extra label to characterize origin of the
transportedmaterial, its transfer mechanisms, and natural versus anthropogenic influences. These new stable
isotope techniques are scalable across a wide range of geographic and temporal scales. This review focuses on
three aspects of hydrological and geochemical river research that are of prime importance to the policy issues
of climate change and include utilization of stable water and carbon isotopes: (i) silicate and carbonate
weathering in river basins, (ii) the riverine carbon and oxygen cycles, and (iii) water balances at the
catchment scale. Most studies at watershed scales currently focus on water and carbon balances but future
applications hold promise to integrate sediment fluxes and turnover, ground and surface water interactions,
as well as the understanding of contaminant sources and their effects in river systems
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A Cross-Sectional Survey of the Association between Bilateral Topical Prostaglandin Analogue Use and Ocular Adnexal Features
We studied the relation between prostaglandin analogue use and ocular adnexal features. We used a prospective, cross-sectional study involving 157 current, 15 past, and 171 never users of prostaglandin analogues. Patients 50 years of age or older and without conditions affecting ocular adnexal anatomy underwent glaucoma medication use history, external digital photography and systematic external adnexal exam. Two masked readers assessed the digital photos for upper lid dermatochalasis and lower lid steatoblepharon using a validated grading scheme. Another masked clinical examiner also assessed upper lid ptosis, levator muscle function, and inferior scleral show. We performed ordinal logistic regression analysis accounting for multiple covariates to assess the relation between prostaglandin analogue use and adnexal features. Multivariable analyses indicated there was a 230-fold increased risk of incremental involution of dermatochalasis (odds ratio (OR) = 2.30; 95% confidence interval (CI) 1.43–3.69; p = 5.44E-04) and a 249-fold increased risk of incremental loss of lower lid steatoblepharon (OR = 2.49; 95% CI, 1.54–4.03; p = 1.98E-04) associated with current prostaglandin analogue use (bimatoprost 0.03%, travoprost 0.005%, or latanoprost 0.004%) versus prostaglandin analogue never or past users. Upper lid ptosis (OR = 4.04; 95% CI, 2.43–6.72; p = 7.37E-08), levator dysfunction (OR = 7.51; 95% CI, 3.39–16.65; p = 6.74E-07) and lower lid retraction (OR = 2.60; 95% CI, 1.58–4.28; p = 1.72E-04) were highly associated with current prostaglandin analogue use versus prostaglandin analogue never or past users. The associations between prostaglandin analogue use and deepening of the upper lid sulci and between prostaglandin analogue use and loss of inferior periorbital fat are confirmed in this multivariable analysis. The associations between prostaglandin analogue use and levator muscle dysfunction and between prostaglandin analogue use and upper lid ptosis represent significant side effects that could impact visual function in glaucoma patients
A perspective on using experiment and theory to identify design principles in dye-sensitized solar cells
Dye-sensitized solar cells (DSCs) have been the subject of wide-ranging studies for many
years because of their potential for large-scale manufacturing using roll-to-roll processing
allied to their use of earth abundant raw materials. Two main challenges exist for DSC
devices to achieve this goal; uplifting device efficiency from the 12 to 14% currently
achieved for laboratory-scale ‘hero’ cells and replacement of the widely-used liquid
electrolytes which can limit device lifetimes. To increase device efficiency requires optimized
dye injection and regeneration, most likely from multiple dyes while replacement
of liquid electrolytes requires solid charge transporters (most likely hole transport materials
– HTMs). While theoretical and experimental work have both been widely applied to
different aspects of DSC research, these approaches are most effective when working in
tandem. In this context, this perspective paper considers the key parameters which
influence electron transfer processes in DSC devices using one or more dye molecules
and how modelling and experimental approaches can work together to optimize electron
injection and dye regeneration.
This paper provides a perspective that theory and experiment are best used in tandem to study
DSC device
A comparison of buoy meteorological systems
During May and June 2000, an intercomparison was made of buoy meteorological
systems from the Woods Hole Oceanographic Institution (WHOI), the National Oceanographic
and Atmospheric Administration (NOAA), Pacific Marine Environmental Laboratory (PMEL),
and the Japanese Marine Science and Technology Center (JAMSTEC). Two WHOI systems
mounted on a 3 m discus buoy, two PMEL systems mounted on separate buoy tower tops and
one JAMSTEC system mounted on a wooden platform were lined parallel to, and 25 m from
Nantucket Sound in Massachusetts. All systems used R. M. Young propeller anemometers,
Rotronic relative humidity and air temperature sensors and Eppley short-wave radiation sensors.
The PMEL and WHOI systems used R. M.Young self-siphoning rain gauges, while the
JAMSTEC system used a Scientific Technology ORG-115 optical rain gauge. The PMEL and
WHOI systems included an Eppley PIR long-wave sensor, while the JAMSTEC had no longwave
sensor. The WHOI system used an AIR DB-1A barometric pressure sensor. PMEL and
JAMSTEC systems used Paroscientific Digiquartz sensors. The Geophysical Instruments and
Measurements Group (GIM) from Brookhaven National Laboratory (BNL) installed two
Portable Radiation Package (PRP) systems that include Eppley short-wave and long-wave
sensors on a platform near the site.
It was apparent from the data that for most of the sensors, the correlation between data
sets was better than the absolute agreement between them. The conclusions made were that the
sensors and associated electronics from the three different laboratories performed comparably.Funding was provided by the National Oceanic and Atmospheric Administration
under Grant Number NA96GPO429
Deep sequencing of blood and gut T-cell receptor beta-chains reveals gluten-induced immune signatures in celiac disease
Celiac disease (CD) patients mount an abnormal immune response to gluten. T-cell receptor (TCR) repertoires directed to some immunodominant gluten peptides have previously been described, but the global immune response to in vivo gluten exposure in CD has not been systematically investigated yet. Here, we characterized signatures associated with gluten directed immune activity and identified gluten-induced T-cell clonotypes from total blood and gut TCR repertoires in an unbiased manner using immunosequencing. CD patient total TCR repertoires showed increased overlap and substantially altered TRBV-gene usage in both blood and gut samples, and increased diversity in the gut during gluten exposure. Using differential abundance analysis, we identified gluten-induced clonotypes in each patient that were composed of a large private and an important public component. Hierarchical clustering of public clonotypes associated with dietary gluten exposure identified subsets of highly similar clonotypes, the most proliferative of which showing significant enrichment for the motif ASS[LF] R[SW][TD][DT][TE][QA][YF] in PBMC repertoires. These results show that CD-associated clonotypes can be identified and that common gluten associated immune response features can be characterized in vivo from total repertoires, with potential use in disease stratification and monitoring.Peer reviewe
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