38 research outputs found
e-Infrastructures for e-Science: A Global View
In the last 10 years, a new way of doing science is spreading in the world thank to the development of virtual research communities across many geographic and administrative boundaries. A virtual research community is a widely dispersed group of researchers and associated scientific instruments working together in a common virtual environment. This new kind of scientific environment, usually addressed as a "collaboratory", is based on the availability of high-speed networks and broadband access, advanced virtual tools and Grid-middleware technologies which, altogether, are the elements of the e-Infrastructures. The European Commission has heavily invested in promoting this new way of collaboration among scientists funding several international projects with the aim of creating e-Infrastructures to enable the European Research Area and connect the European researchers with their colleagues based in Africa, Asia and Latin America. In this paper we describe the actual status of these e- Infrastructures and present a complete picture of the virtual research communities currently using them. Information on the scientific domains and on the applications supported are provided together with their geographic distribution
CAESAR source finder: recent developments and testing
A new era in radioastronomy will begin with the upcoming large-scale surveys
planned at the Australian Square Kilometre Array Pathfinder (ASKAP). ASKAP
started its Early Science program in October 2017 and several target fields
were observed during the array commissioning phase. The SCORPIO field was the
first observed in the Galactic Plane in Band 1 (792-1032 MHz) using 15
commissioned antennas. The achieved sensitivity and large field of view already
allow to discover new sources and survey thousands of existing ones with
improved precision with respect to previous surveys. Data analysis is currently
ongoing to deliver the first source catalogue. Given the increased scale of the
data, source extraction and characterization, even in this Early Science phase,
have to be carried out in a mostly automated way. This process presents
significant challenges due to the presence of extended objects and diffuse
emission close to the Galactic Plane. In this context we have extended and
optimized a novel source finding tool, named CAESAR , to allow extraction of
both compact and extended sources from radio maps. A number of developments
have been done driven by the analysis of the SCORPIO map and in view of the
future ASKAP Galactic Plane survey. The main goals are the improvement of
algorithm performances and scalability as well as of software maintainability
and usability within the radio community. In this paper we present the current
status of CAESAR and report a first systematic characterization of its
performance for both compact and extended sources using simulated maps. Future
prospects are discussed in light of the obtained results.Comment: 15 pages, 10 figure
Big Data Analytics for Earth Sciences: the EarthServer approach
Big Data Analytics is an emerging field since massive storage and computing capabilities have been made available by advanced e-infrastructures. Earth and Environmental sciences are likely to benefit from Big Data Analytics techniques supporting the processing of the large number of Earth Observation datasets currently acquired and generated through observations and simulations. However, Earth Science data and applications present specificities in terms of relevance of the geospatial information, wide heterogeneity of data models and formats, and complexity of processing. Therefore, Big Earth Data Analytics requires specifically tailored techniques and tools. The EarthServer Big Earth Data Analytics engine offers a solution for coverage-type datasets, built around a high performance array database technology, and the adoption and enhancement of standards for service interaction (OGC WCS and WCPS). The EarthServer solution, led by the collection of requirements from scientific communities and international initiatives, provides a holistic approach that ranges from query languages and scalability up to mobile access and visualization. The result is demonstrated and validated through the development of lighthouse applications in the Marine, Geology, Atmospheric, Planetary and Cryospheric science domains
Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project
In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory
Fetal Abdominal Aorta: Doppler and Structural Evaluation of Endothelial Function in Intrauterine Growth Restriction and Controls
Purpose 'The human aorta stores strain energy in the distended wall during systole through the extracellular matrix of the tunica media that could be influenced by blood pressure, flow, or increased peripheral resistance. In intrauterine growth restriction (IUGR) fetuses, the increased aorta intima media thickness (aIMT) could reflect a different extracellular matrix composition and, therefore, functionality. The aim of this study was to analyze the resistance to flow in the fetal descending aorta and its relation to aIMT and systolic and diastolic fetal abdominal aorta diameters in IUGR fetuses and controls. Materials and Methods This is a prospective case control study of single pregnancies collected at a tertiary center for feto-maternal medicine in Northeast Italy. An IUGR group as cases and a group of fetuses appropriate for gestational age (AGA) as controls were included. Results We found a greater PI of the fetal abdominal aorta in the IUGR group (1.82) than in the AGA group (1.21) (p<0.05). The change between the systolic and diastolic fetal abdominal aorta diameters was significantly greater in IUGR fetuses (0.10mm (IQR 0.07-0.28)) than in the AGA group (0.04mm (0.03-0.05)) (p<0.05). In the IUGR group aIMT was significantly correlated with peak systolic velocity (PSV) and systolic-diastolic aorta diameter change, while these two correlations were not found in the control group. Conclusion The change between the systolic and diastolic fetal abdominal aorta diameters in IUGR cases during the early third trimester of pregnancy was significantly increased and aIMT in the IUGR group was significantly correlated to systolic-diastolic diameter change and PSV, probably reflecting aortic wall adaptation to blood flow changes in IUGR fetuses