587 research outputs found

    LSST Science Data Quality Analysis Subsystem Design

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    The Large Synoptic Survey Telescope (LSST) will have a Science Data Quality Analysis (SDQA) subsystem for vetting its unprecedented volume of astronomical image data. The SDQA subsystem inhabits three basic realms: image processing, graphical-user-interface (GUI) tools, and alarms/reporting. During pipeline image processing, SDQA data are computed for the images and astronomical sources extracted from the images, and utilized to grade the images and sources. Alarms are automatically sent, if necessary, to initiate swift response to problems found. Both SDQA data and machine-determined grades are stored in a database. At the end of a data-processing interval, e.g., nightly processing or data-release reprocessing, automatic SDQA reports are generated from SDQA data and grades queried from the database. The SDQA reports summarize the science data quality and provide feedback to telescope, camera, facility, observation-scheduling and data-processing personnel. During operations, GUI tools facilitate visualization of image and SDQA data in a variety of ways that allow a small SDQA-operations team of humans to quickly and easily perform manual SDQA on a substantial fraction of LSST data products, and possibly reassign SDQA grades as a result of the visual inspection

    High performance astronomical data communications in the LSST data management system

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    The Large Synoptic Survey Telescope (LSST) is an 8.4m (6.5m effective), wide-field (9.6 degree2), ground-based telescope with a 3.2 GPixel camera. It will survey over 20,000 degree2 with 1,000 re-visits over 10 years in six visible bands, and is scheduled to begin full scientific operations in 2016. The Data Management System will acquire and process the images, issue transient alerts, and catalog the world's largest database of optical astronomical data. Every 24 hours, 15 terabytes of raw data will be transferred via redundant 10 Gbps fiber optics down from the mountain summit at Cerro Pachon, Chile to the Base Facility in La Serena for transient alert processing. Simultaneously, the data will be transferred at 2.5Gbps over fiber optics to the Archive Center in Champaign, Illinois for archiving and further scientific processing and creation of scientific data catalogs. Finally, the Archive Center will distribute the processed data and catalogs at 10Gbps to a number Data Access Centers for scientific ,educational, and public access. Redundant storage and network bandwidth is built into the design of the system. The current networking acquistiion strategy involves leveraging existing dark fiber to handle within Chile, Chile - U.S. and within U.S. links. There are a significant number of carriers and networks involved and coordinating the acquisition, deployment, and operations of this capability. Advanced protocols are being investigated during our Research and Development phase to address anticipated challenges in effective utilization. We describe the data communications requirements, architecture, and acquisition strategy in this paper

    High performance astronomical data communications in the LSST data management system

    Get PDF
    The Large Synoptic Survey Telescope (LSST) is an 8.4m (6.5m effective), wide-field (9.6 degree2), ground-based telescope with a 3.2 GPixel camera. It will survey over 20,000 degree2 with 1,000 re-visits over 10 years in six visible bands, and is scheduled to begin full scientific operations in 2016. The Data Management System will acquire and process the images, issue transient alerts, and catalog the world's largest database of optical astronomical data. Every 24 hours, 15 terabytes of raw data will be transferred via redundant 10 Gbps fiber optics down from the mountain summit at Cerro Pachon, Chile to the Base Facility in La Serena for transient alert processing. Simultaneously, the data will be transferred at 2.5Gbps over fiber optics to the Archive Center in Champaign, Illinois for archiving and further scientific processing and creation of scientific data catalogs. Finally, the Archive Center will distribute the processed data and catalogs at 10Gbps to a number Data Access Centers for scientific ,educational, and public access. Redundant storage and network bandwidth is built into the design of the system. The current networking acquistiion strategy involves leveraging existing dark fiber to handle within Chile, Chile - U.S. and within U.S. links. There are a significant number of carriers and networks involved and coordinating the acquisition, deployment, and operations of this capability. Advanced protocols are being investigated during our Research and Development phase to address anticipated challenges in effective utilization. We describe the data communications requirements, architecture, and acquisition strategy in this paper

    Genetic Analysis of the Early Natural History of Epithelial Ovarian Carcinoma

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    The high mortality rate associated with epithelial ovarian carcinoma (EOC) reflects diagnosis commonly at an advanced stage, but improved early detection is hindered by uncertainty as to the histologic origin and early natural history of this malignancy.Here we report combined molecular genetic and morphologic analyses of normal human ovarian tissues and early stage cancers, from both BRCA mutation carriers and the general population, indicating that EOCs frequently arise from dysplastic precursor lesions within epithelial inclusion cysts. In pathologically normal ovaries, molecular evidence of oncogenic stress was observed specifically within epithelial inclusion cysts. To further explore potential very early events in ovarian tumorigenesis, ovarian tissues from women not known to be at high risk for ovarian cancer were subjected to laser catapult microdissection and gene expression profiling. These studies revealed a quasi-neoplastic expression signature in benign ovarian cystic inclusion epithelium compared to surface epithelium, specifically with respect to genes affecting signal transduction, cell cycle control, and mitotic spindle formation. Consistent with this gene expression profile, a significantly higher cell proliferation index (increased cell proliferation and decreased apoptosis) was observed in histopathologically normal ovarian cystic compared to surface epithelium. Furthermore, aneuploidy was frequently identified in normal ovarian cystic epithelium but not in surface epithelium.Together, these data indicate that EOC frequently arises in ovarian cystic inclusions, is preceded by an identifiable dysplastic precursor lesion, and that increased cell proliferation, decreased apoptosis, and aneuploidy are likely to represent very early aberrations in ovarian tumorigenesis

    Involvement of right dorsolateral prefrontal cortex in ill-structured design cognition: An fMRI study

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    In ill-structured tasks, the problem to be solved is poorly specified and there is no unique correct solution. Most evidence on brain mechanisms involved in dealing with such tasks comes from neuropsychology. Here, we developed an ill-structured design task suitable for testing in a functional neuroimaging environment and compared it with a matched well-structured problem-solving task using fMRI. Consistent with prior neuropsychological results, the design task was associated with greater activity in right dorsolateral prefrontal cortex compared with problem solving. This differential activity was specific to the problem studying phase rather than performance. Furthermore, the design and problem-solving tasks differed not only in overall levels of brain activity but also in patterns of functional interactions between brain regions. These results provide new evidence on the role of right dorsolateral prefrontal cortex in ill-structured situations, such as those involved in design cognition. Additionally, these results confirm the suitability of functional neuroimaging for studying such situations

    Invasive Plant Suppresses the Growth of Native Tree Seedlings by Disrupting Belowground Mutualisms

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    The impact of exotic species on native organisms is widely acknowledged, but poorly understood. Very few studies have empirically investigated how invading plants may alter delicate ecological interactions among resident species in the invaded range. We present novel evidence that antifungal phytochemistry of the invasive plant, Alliaria petiolata, a European invader of North American forests, suppresses native plant growth by disrupting mutualistic associations between native canopy tree seedlings and belowground arbuscular mycorrhizal fungi. Our results elucidate an indirect mechanism by which invasive plants can impact native flora, and may help explain how this plant successfully invades relatively undisturbed forest habitat

    Ab-Externo AAV-Mediated Gene Delivery to the Suprachoroidal Space Using a 250 Micron Flexible Microcatheter

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    The current method of delivering gene replacement to the posterior segment of the eye involves a three-port pars plana vitrectomy followed by injection of the agent through a 37-gauge cannula, which is potentially wrought with retinal complications. In this paper we investigate the safety and efficacy of delivering adeno-associated viral (AAV) vector to the suprachoroidal space using an ab externo approach that utilizes an illuminated microcatheter.6 New Zealand White rabbits and 2 Dutch Belted rabbits were used to evaluate the ab externo delivery method. sc-AAV5-smCBA-hGFP vector was delivered into the suprachoroidal space using an illuminated iTrackTM 250A microcatheter. Six weeks after surgery, the rabbits were sacrificed and their eyes evaluated for AAV transfection using immunofluorescent antibody staining of GFP.Immunostaining of sectioned and whole-mounted eyes demonstrated robust transfection in all treated eyes, with no fluorescence in untreated control eyes. Transfection occurred diffusely and involved both the choroid and the retina. No apparent adverse effects caused by either the viral vector or the procedure itself could be seen either clinically or histologically.The ab externo method of delivery using a microcatheter was successful in safely and effectively delivering a gene therapy agent to the suprachoroidal space. This method presents a less invasive alternative to the current method of virally vectored gene delivery

    Syntactic microvariation and methodology: problems and perspectives

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    Variation in empirical data has been a perseverant problem for theoretical linguistics, especially syntax. Data inconsistencies among authors allegedly analyzing the same phenomenon are ubiquitous in the syntactic literature (e.g., literature on focus-raising in Hungarian; É. Kiss 1987 vs. Lipták 1998), and partly result from the highly informal methodology of data collection. However, even if adequate controls are used to exclude potential biases, variation might remain. The general practice in syntactic research has been to ignore these „microvariations”-mainly in the lack of any systematic empirical method to detect them. The present paper shows that this practice leads to serious theoretical problems and proposes a new empirical method, cluster analysis, to discover, explore and systematize these variations. It also illustrates how this richer empirical basis gives rise to a more fine-grained theoretical analysis
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