16 research outputs found
Application of ESE Data and Tools to Air Quality Management: Services for Helping the Air Quality Community use ESE Data (SHAirED)
The goal of this REASoN applications and technology project is to deliver and use Earth Science Enterprise (ESE) data and tools in support of air quality management. Its scope falls within the domain of air quality management and aims to develop a federated air quality information sharing network that includes data from NASA, EPA, US States and others. Project goals were achieved through a access of satellite and ground observation data, web services information technology, interoperability standards, and air quality community collaboration. In contributing to a network of NASA ESE data in support of particulate air quality management, the project will develop access to distributed data, build Web infrastructure, and create tools for data processing and analysis. The key technologies used in the project include emerging web services for developing self describing and modular data access and processing tools, and service oriented architecture for chaining web services together to assemble customized air quality management applications. The technology and tools required for this project were developed within DataFed.net, a shared infrastructure that supports collaborative atmospheric data sharing and processing web services. Much of the collaboration was facilitated through community interactions through the Federation of Earth Science Information Partners (ESIP) Air Quality Workgroup. The main activities during the project that successfully advanced DataFed, enabled air quality applications and established community-oriented infrastructures were: develop access to distributed data (surface and satellite), build Web infrastructure to support data access, processing and analysis create tools for data processing and analysis foster air quality community collaboration and interoperability
Overexpression of the UGT73C6 alters brassinosteroid glucoside formation in Arabidopsis thaliana
<p>Abstract</p> <p>Background</p> <p>Brassinosteroids (BRs) are signaling molecules that play essential roles in the spatial regulation of plant growth and development. In contrast to other plant hormones BRs act locally, close to the sites of their synthesis, and thus homeostatic mechanisms must operate at the cellular level to equilibrate BR concentrations. Whilst it is recognized that levels of bioactive BRs are likely adjusted by controlling the relative rates of biosynthesis and by catabolism, few factors, which participate in these regulatory events, have as yet been identified. Previously we have shown that the UDP-glycosyltransferase UGT73C5 of <it>Arabidopsis thaliana </it>catalyzes 23-<it>O</it>-glucosylation of BRs and that glucosylation renders BRs inactive. This study identifies the closest homologue of UGT73C5, UGT73C6, as an enzyme that is also able to glucosylate BRs <it>in planta</it>.</p> <p>Results</p> <p>In a candidate gene approach, in which homologues of UGT73C5 were screened for their potential to induce BR deficiency when over-expressed in plants, UGT73C6 was identified as an enzyme that can glucosylate the BRs CS and BL at their 23-<it>O</it>-positions <it>in planta</it>. GUS reporter analysis indicates that <it>UGT73C6 </it>shows over-lapping, but also distinct expression patterns with <it>UGT73C5 </it>and YFP reporter data suggests that at the cellular level, both UGTs localize to the cytoplasm and to the nucleus. A liquid chromatography high-resolution mass spectrometry method for BR metabolite analysis was developed and applied to determine the kinetics of formation and the catabolic fate of BR-23-<it>O</it>-glucosides in wild type and <it>UGT73C5 </it>and <it>UGT73C6 </it>over-expression lines. This approach identified novel BR catabolites, which are considered to be BR-malonylglucosides, and provided first evidence indicating that glucosylation protects BRs from cellular removal. The physiological significance of BR glucosylation, and the possible role of UGT73C6 as a regulatory factor in this process are discussed in light of the results presented.</p> <p>Conclusion</p> <p>The present study generates essential knowledge and molecular and biochemical tools, that will allow for the verification of a potential physiological role of UGT73C6 in BR glucosylation and will facilitate the investigation of the functional significance of BR glucoside formation in plants.</p
The 2001 Superoutburst of WZ Sagittae
We report the results of a worldwide campaign to observe WZ Sagittae during
its 2001 superoutburst. After a 23-year slumber at V=15.5, the star rose within
2 days to a peak brightness of 8.2, and showed a main eruption lasting 25 days.
The return to quiescence was punctuated by 12 small eruptions, of ~1 mag
amplitude and 2 day recurrence time; these "echo outbursts" are of uncertain
origin, but somewhat resemble the normal outbursts of dwarf novae. After 52
days, the star began a slow decline to quiescence.
Periodic waves in the light curve closely followed the pattern seen in the
1978 superoutburst: a strong orbital signal dominated the first 12 days,
followed by a powerful /common superhump/ at 0.05721(5) d, 0.92(8)% longer than
P_orb. The latter endured for at least 90 days, although probably mutating into
a "late" superhump with a slightly longer mean period [0.05736(5) d]. The
superhump appeared to follow familiar rules for such phenomena in dwarf novae,
with components given by linear combinations of two basic frequencies: the
orbital frequency omega_o and an unseen low frequency Omega, believed to
represent the accretion disk's apsidal precession. Long time series reveal an
intricate fine structure, with ~20 incommensurate frequencies. Essentially all
components occurred at a frequency n(omega_o)-m(Omega), with m=1, ..., n. But
during its first week, the common superhump showed primary components at n
(omega_o)-Omega, for n=1, 2, 3, 4, 5, 6, 7, 8, 9 (i.e., m=1 consistently); a
month later, the dominant power shifted to components with m=n-1. This may
arise from a shift in the disk's spiral-arm pattern, likely to be the
underlying cause of superhumps.
The great majority of frequency components ... . (etc., abstract continues)Comment: PDF, 54 pages, 4 tables, 21 figures, 1 appendix; accepted, in press,
to appear July 2002, PASP; more info at http://cba.phys.columbia.edu
DataFed: An Architecture for Federating Atmospheric Data for GEOSS
Abstract-DataFed is a distributed web-services-based computing environment for accessing, processing and rendering environmental data in support of air quality management and science. The flexible, adoptive environment facilitates the access and flow of atmospheric data from provider to users by enabling the creation of user-driven data processing value chains. The approach of DataFed is mediation between users and data providers. DataFed assumes the autonomous and spontaneous emergence of distributed data sources. It non-intrusively wraps datasets for access by web services. The mediator software, composed of web services, provides homogeneous data views (e.g. geospatial, time views) using a global multi-dimensional data model. Application software written using web services consists of data browsers and analysis tools for distributed AQ data. Currently DataFed serves as data gateway for user programs; web pages, GIS, science tools as well as for loosely coupled Service Oriented Architecture Applications. Its federated data pool consists of over 50 datasets and the tools have been applied in several air pollution projects Index Terms-Earth environment, terrestrial atmosphere, information system