Remote sensing applications to hydrologic modeling

An energy balance snowmelt model for rugged terrain was devised and coupled to a flow model. A literature review of remote sensing applications to hydrologic modeling was included along with a software development outline

Data Mining by Grid Computing in the Search for Extrasolar Planets

A system is presented here to provide improved precision in ensemble differential photometry. This is achieved by using the power of grid computing to analyse astronomical catalogues. This produces new catalogues of optimised pointings for each star, which maximise the number and quality of reference stars available. Astronomical phenomena such as exoplanet transits and small-scale structure within quasars may be observed by means of millimagnitude photometric variability on the timescale of minutes to hours. Because of atmospheric distortion, ground-based observations of these phenomena require the use of differential photometry whereby the target is compared with one or more reference stars. CCD cameras enable the use of many reference stars in an ensemble. The more closely the reference stars in this ensemble resemble the target, the greater the precision of the photometry that can be achieved. The Locus Algorithm has been developed to identify the optimum pointing for a target and provide that pointing with a score relating to the degree of similarity between target and the reference stars. It does so by identifying potential points of aim for a particular telescope such that a given target and a varying set of references were included in a field of view centred on those pointings. A score is calculated for each such pointing. For each target, the pointing with the highest score is designated the optimum pointing. The application of this system to the Sloan Digital Sky Survey (SDSS) catalogue demanded the use of a High Performance Computing (HPC) solution through Grid Ireland. Pointings have thus been generated for 61,662,376 stars and 23,697 quasars

AXMEDIS 2008

The AXMEDIS International Conference series aims to explore all subjects and topics related to cross-media and digital-media content production, processing, management, standards, representation, sharing, protection and rights management, to address the latest developments and future trends of the technologies and their applications, impacts and exploitation. The AXMEDIS events offer venues for exchanging concepts, requirements, prototypes, research ideas, and findings which could contribute to academic research and also benefit business and industrial communities. In the Internet as well as in the digital era, cross-media production and distribution represent key developments and innovations that are fostered by emergent technologies to ensure better value for money while optimising productivity and market coverage

Multimedia

The nowadays ubiquitous and effortless digital data capture and processing capabilities offered by the majority of devices, lead to an unprecedented penetration of multimedia content in our everyday life. To make the most of this phenomenon, the rapidly increasing volume and usage of digitised content requires constant re-evaluation and adaptation of multimedia methodologies, in order to meet the relentless change of requirements from both the user and system perspectives. Advances in Multimedia provides readers with an overview of the ever-growing field of multimedia by bringing together various research studies and surveys from different subfields that point out such important aspects. Some of the main topics that this book deals with include: multimedia management in peer-to-peer structures & wireless networks, security characteristics in multimedia, semantic gap bridging for multimedia content and novel multimedia applications

CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines

Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective. The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines. From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research

Co-phasing segmented mirrors: theory, laboratory experiments and measurements on sky

Future Extremely Large Telescopes (ELTs) will be segmented. To achieve the desired image quality, in particular for high contrast imaging, the segments of the primary mirror must be phased to an accuracy which corresponds to a small fraction of the observing wavelength. Information on the misalignments of the segments of the primary mirror will be provided with a phasing camera. The Zernike phase contrast method is a novel technique to phase the primary mirrors of segmented telescopes. The present thesis aims at studying the phasing of segmented mirrors using the Zernike phase contrast method. The theoretical background of this sensor and the algorithm used to retrieve the piston, tip, and tilt information are described. The Zernike Phase Contrast Sensor has been tested in the laboratory and on-sky on a Unit Telescope of the ESO Very Large Telescope with a segmented mirror conjugated to its primary mirror to emulate a segmented telescope. The performance of the sensor as a function of various parameters such as star magnitude, seeing, and integration time is discussed. The phasing accuracy obtained on sky has always been below 15 nm root mean square wavefront error under normal conditions of operation. Equivalent limiting star magnitudes of 18 and 15.7 achieved in the laboratory and on-sky, respectively, with this sensor would be sufficient to phase segmented telescopes in closed-loop during observations

In vivo and in vitro developmental study of porcine testis cells and tissue

Testis development and function involve multiple cell types and require complex cellular interactions and signaling cascades; hence, the study of these processes necessitates improvement of ex situ models of testicular cells or tissue. Accordingly, objectives of the first and second studies in this thesis were to improve in vitro culture of testis cells by testing the effects of various culture components on proliferation, colony-formation, and potency of germline stem cells. The examined components included different media, serum types, and several key growth factors, tested in sequential experiments using a factorial design. The third study focused on assessment of pluripotency of cultured neonatal porcine gonocytes and their potential to trans-differentiae into somatic cells of different cell lineages. The goal of our fourth study was to investigate the feasibility of applying ultrasound biomicroscopy (UBM) for the assessment of testis tissue grafts and cell implants by initially validating its use in a short-term study. In the fifth study, we examined repeated application of UBM in a longitudinal manner to test its reliability and accuracy in representing the developmental changes in grafts and implants. As a result, we showed increased proliferation of porcine gonocytes with a given culture condition combination (DMEM+15% FBS), followed by attainment of pluripotency markers by cultured gonocytes and their colonies, indicative of their spontaneous transformation into a pluripotent state. Supplementation of certain growth factors at a given concentration to the base media also led to further increases in gonocyte numbers and colony diameters, while maintaining their expression of pluripotency and germ cell markers. We also observed successful derivation of somatic cells of different lineages from germ cell originated-pluripotent stem cells. Furthermore, application of UBM for non-invasive in vivo developmental study of testicular grafts and implants was shown to be accurate and reliable, thereby reducing the number of animals needed in future similar experiments. Taken together, the studies describe improved germ cell culture conditions, transformation of gonocytes into a pluripotent state, as well as validating and using UBM as an accurate and reliable tool for in vivo developmental study of testis grafts and implants

High-contrast imaging study of exoplanets and circumstellar disks

High-contrast imaging provides an excellent tool to detect and characterise exoplanets and circumstellar disks. Understanding the connection between them is key for the improvement of planet formation and evolution theories. In this thesis, I analyse near-infrared (NIR) observations obtained with the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) to look into various stages of the evolution of planetary systems. I combine the high-contrast imaging technique with observations in the millimetre continuum, hydrodynamical simulations, and radiative transfer models, as well as atmospheric retrievals and self-consistent models to analyse and interpret the different systems. Starting with protoplanetary disks as the birthplaces of planets, I study the morphology of the disk around WaOph 6 at different wavelengths (NIR and millimetre continuum) and find the presence of spiral arms in scattered light for the first time in such a young disk. Additionally, I test the hypothesis of a planet driving the architecture of the disk through hydrodynamical simulations and radiative transfer. Moving on to more evolved systems, I first demonstrate the use of the high-contrast imaging technique to characterise companion candidates and to determine their membership to the system. Furthermore, I analyse spectro-photometric data of the exoplanet 51 Eridani b and apply an atmospheric retrieval to estimate the physical parameters of the planet, revisiting previously reported values and finding a cloud-free atmosphere. Finally, I analyse a sample of debris disks with a double belt architecture inferred via SED modelling. I present mass and location estimates of planets that may be orbiting in the gaps between the belts, as well as detection limits from the observations and plans for future research. This thesis illustrates the current challenges in our understanding of planet formation and evolution and provides possible paths to overcome them