45 research outputs found

    Wildfire monitoring via the integration of remote sensing with innovative information technologies

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    In the Institute for Space Applications and Remote Sensing of the National Observatory of Athens (ISARS/NOA) volumes of Earth Observation images of different spectral and spatial resolutions are being processed on a systematic basis to derive thematic products that cover a wide spectrum of applications during and after wildfire crisis, from fire detection and fire-front propagation monitoring, to damage assessment in the inflicted areas. The processed satellite imagery is combined with auxiliary geo-information layers, including land use/land cover, administrative boundaries, road and rail network, points of interest, and meteorological data to generate and validate added-value fire-related products. The service portfolio has become available to institutional End Users with a mandate to act on natural disasters and that have activated Emergency Support Services at a European level in the framework of the operational GMES projects SAFER and LinkER. Towards the goal of delivering integrated services for fire monitoring and management, ISARS/NOA employs observational capacities which include the operation of MSG/SEVIRI and NOAA/AVHRR receiving stations, NOA's in-situ monitoring networks for capturing meteorological parameters to generate weather forecasts, and datasets originating from the European Space Agency and third party satellite operators. The qualified operational activity of ISARS/NOA in the domain of wildfires management is highly enhanced by the integration of state-of-the-art Information Technologies that have become available in the framework of the TELEIOS (EC/ICT) project. TELEIOS aims at the development of fully automatic processing chains reliant on a) the effective storing and management of the large amount of EO and GIS data, b) the post-processing refinement of the fire products using semantics, and c) the creation of thematic maps and added-value services. The first objective is achieved with the use of advanced Array Database technologies, such as MonetDB, to enable efficiency in accessing large archives of image data and metadata in a fully transparent way, without worrying for their format, size, and location, as well as efficiency in processing such data using state-of-the-art implementations of image processing algorithms expressed in a high-level Scientific Query Language (SciQL). The product refinement is realized through the application of update operations that incorporate human evidence and human logic, with semantic content extracted from thematic information coming from auxiliary geo-information layers and sources, for reducing considerably the number of false alarms in fire detection, and improving the credibility of the burnt area assessment. The third objective is approached via the combination of the derived fire-products with Linked Geospatial Data, structured accordingly and freely available in the web, using Semantic Web technologies. These technologies are built on top of a robust and modular computational environment, to facilitate several wildfire applications to run efficiently, such as real-time fire detection, fire-front propagation monitoring, rapid burnt area mapping, after crisis detailed burnt scar mapping, and time series analysis of burnt areas. The approach adopted allows ISARS/NOA to routinely serve requests from the end-user community, irrespective of the area of interest and its extent, the observation time period, or the data volume involved, granting the opportunity to combine innovative IT solutions with remote sensing techniques and

    Operational Wildfire Monitoring and Disaster Management Support Using State-of-the-art EO and Information Technologies

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    Fires have been one of the main driving forces in the evolution of plants and ecosystems, determining the current structure and composition of the Landscapes. However, significant alterations in the fire regime have occurred in the recent decades, primarily as a result of socioeconomic changes, increasing dramatically the catastrophic impacts of wildfires as it is reflected in the increase during the 20th century of both, number of fires and the annual area burnt. Therefore, the establishment of a permanent robust fire monitoring system is of paramount importance to implement an effective environmental management policy. Such an integrated system has been developed in the Institute for Space Applications and Remote Sensing of the National Observatory of Athens (ISARS/NOA). Volumes of Earth Observation images of different spectral and spatial resolutions are being processed on a systematic basis to derive thematic products that cover a wide spectrum of applications during and after wildfire crisis, from fire detection and fire-front propagation monitoring, to damage assessment in the inflicted areas. The processed satellite imagery is combined with auxiliary geo-information layers and meteorological data to generate and validate added-value fire-related products. The service portfolio has become available to institutional End Users with a mandate to act on natural disasters in the framework of the operational GMES projects SAFER and LinkER addressing fire emergency response and emergency support needs for the entire European Union. Towards the goal of delivering integrated services for fire monitoring and management, ISARS/NOA employs observational capacities which include the operation of MSG/SEVIRI and NOAA/AVHRR receiving stations, NOA’s in-situ monitoring networks for capturing meteorological parameters to generate weather forecasts, and datasets originating from the European Space Agency and third party satellite operators. The qualified operational activity of ISARS/NOA in the domain of wildfires management is highly enhanced by the integra

    Implantation of MNNG crystals into a Triturus intact limb affects mitotic and labeling indices, regeneration rate, and morphogenesis in the contralateral, regenerating limb

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    Experimental administration of chemical carcinogens to various mammals is highly effective in inducing malignant tumors. In contrast, treatment of regeneration-competent animals even with much higher doses of the same drugs only exceptionally leads to tumor-like growth. Usually, carcinogenic materials implanted or injected into a regenerating limb of urodele amphibia interfere with the regenerative process and frequently lead a) to growth retardation or arrest of regeneration, b) to development of a great variety of abnormal regenerates, and c) to generation of accessory, limb-like structures. Autonomous or experimental incidence of carcinogenesis is extremely low in animals endowed with strong regenerative capabilities. Of exceptional biological significance is the fact that such induced tumors usually regress spontaneously. This unique property of the regeneration-competent animals to resist carcinogenesis provides opportunities to compare non-cancerous alterations in the differentiated state of adult cells to those occurring in neoplasia. The mode of action of the chemical carcinogens on limb regeneration has not yet been clarified with certainty at the cellular and the molecular level. Several scientists claim that the above-mentioned effects might be attributed to local toxic influences of the drugs; therefore the present study was designed to investigate whether the administration of the carcinogen MNNG can affect cell proliferation, histogenesis, and morphogenesis at a region distant from the site of its implantation, even after a relatively long time period. To this end, 40 animals of the species Triturus cristatus had their right hindlimb surgically removed at the distal zeugopod. Then, a small microcrystal (approximately 5 μg) of MNNG was inserted under the ventral aspect of the skin of the left tarsus in 20 of these animals (groups T and A; see below). Two months later, nine of the MNNG-treated animals were injected intraperitoneally with tritiated thymidine. After 2 h, six of these animals had their right hindlimb amputated at the distal zeugopod, whereas the rest were left to regenerate. The results were evaluated by camera lucida drawings, clearing in methyl benzoate, classical histology, and autoradiography. It was revealed that administration of MNNG at a somatic region (left hindlimb) reduces DNA synthesis and mitosis at a distant place (right hindlimb) even 2 months after MNNG implantation. Despite this, the rate of limb elongation is not substantially reduced. Classical histology revealed normal tissue structure throughout. All regenerated limbs displayed several teratogenic abnormalities. © 2002 Wiley-Liss, Inc

    An Online System for Nowcasting Satellite Derived Temperatures for Urban Areas

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    The Urban Heat Island (UHI) is an adverse environmental effect of urbanization that increases the energy demand of cities and impacts human health. The study of this effect for monitoring and mitigation purposes is crucial, but it is hampered by the lack of high spatiotemporal temperature data. This article presents the work undertaken for the implementation of an operational real-time module for monitoring 2 m air temperature (TA) at a spatial resolution of 1 km based on the Meteosat Second Generation—Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI). This new module has been developed in the context of an operational system for monitoring the urban thermal environment. The initial evaluation of TA products against meteorological in situ data from 15 cities in Europe and North Africa yields that its accuracy in terms of Root Mean Square Error (RMSE) is 2.3 °C and Pearson’s correlation coefficient (Rho) is 0.95. The temperature information made available at and around cities can facilitate the assessment of the UHIs in real time but also the timely generation of relevant higher value products and services for energy demand and human health studies. The service is available at http://snf-652558.vm.okeanos.grnet.gr/treasure/portal/info.html

    Implantation of MNNG crystals into a Triturus intact limb affects mitotic and labeling indices, regeneration rate, and morphogenesis in the contralateral, regenerating limb

    No full text
    Experimental administration of chemical carcinogens to various mammals is highly effective in inducing malignant tumors. In contrast, treatment of regeneration-competent animals even with much higher doses of the same drugs only exceptionally leads to tumor-like growth. Usually, carcinogenic materials implanted or injected into a regenerating limb of urodele amphibia interfere with the regenerative process and frequently lead a) to growth retardation or arrest of regeneration, b) to development of a great variety of abnormal regenerates, and c) to generation of accessory, limb-like structures. Autonomous or experimental incidence of carcinogenesis is extremely low in animals endowed with strong regenerative capabilities. Of exceptional biological significance is the fact that such induced tumors usually regress spontaneously. This unique property of the regeneration-competent animals to resist carcinogenesis provides opportunities to compare non-cancerous alterations in the differentiated state of adult cells to those occurring in neoplasia. The mode of action of the chemical carcinogens on limb regeneration has not yet been clarified with certainty at the cellular and the molecular level. Several scientists claim that the above-mentioned effects might be attributed to local toxic influences of the drugs; therefore the present study was designed to investigate whether the administration of the carcinogen MNNG can affect cell proliferation, histogenesis, and morphogenesis at a region distant from the site of its implantation, even after a relatively long time period. To this end, 40 animals of the species Triturus cristatus had their right hindlimb surgically removed at the distal zeugopod. Then, a small microcrystal (approximately 5 μg) of MNNG was inserted under the ventral aspect of the skin of the left tarsus in 20 of these animals (groups T and A; see below). Two months later, nine of the MNNG-treated animals were injected intraperitoneally with tritiated thymidine. After 2 h, six of these animals had their right hindlimb amputated at the distal zeugopod, whereas the rest were left to regenerate. The results were evaluated by camera lucida drawings, clearing in methyl benzoate, classical histology, and autoradiography. It was revealed that administration of MNNG at a somatic region (left hindlimb) reduces DNA synthesis and mitosis at a distant place (right hindlimb) even 2 months after MNNG implantation. Despite this, the rate of limb elongation is not substantially reduced. Classical histology revealed normal tissue structure throughout. All regenerated limbs displayed several teratogenic abnormalities. © 2002 Wiley-Liss, Inc

    Improving the Downscaling of Diurnal Land Surface Temperatures Using the Annual Cycle Parameters as Disaggregation Kernels

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    The downscaling of geostationary diurnal thermal data can ease the lack of land surface temperature (LST) datasets that combine high spatial and temporal resolution. However, the downscaling of diurnal LST data is more demanding than single scenes. This is because the spatiotemporal interrelationships of the original LST data have to be preserved and accurately reproduced by the downscaled LST (DLST) data. To that end, LST disaggregation kernels/predictors that provide information about the spatial distribution of LST during different times of a day can prove especially useful. Such LST predictors are the LST Annual Cycle Parameters (ACPs). In this work, multitemporal ACPs are employed for downscaling daytime and nighttime ~4 km geostationary LST from SEVIRI (Spinning Enhanced Visible and Infrared Imager) down to 1 km. The overall goal is to assess if the use of the ACPs can improve the estimation of the diurnal range of DLST (daytime DLST minus nighttime DLST). The evaluation is performed by comparing the DLST diurnal range maps with reference data from MODIS (Moderate Imaging Spectroradiometer) and also with data retrieved from a modified version of the TsHARP (Thermal Sharpening) algorithm. The results suggest that the ACPs increase the downscaling performance, improve the estimation of diurnal DLST range and produce more accurate spatial patterns

    Development of an operational modeling system for urban heat islands: an application to Athens, Greece

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    The urban heat island (UHI) effect is one prominent form of localized anthropogenic climate modification. It represents a significant urban climate problem since it occurs in the layer of the atmosphere where almost all daily human activities take place. This paper presents the development of a high-resolution modeling system that could be used for simulating the UHI effect in the context of operational weather forecasting activities. The modeling system is built around a state-of-the-art numerical weather prediction model, properly modified to allow for the better representation of the urban climate. The model performance in terms of simulating the near-surface air temperature and thermal comfort conditions over the complex urban area of Athens, Greece, is evaluated during a 1.5-month operational implementation in the summer of 2010. Results from this case study reveal an overall satisfactory performance of the modeling system. The discussion of the results highlights the important role that, given the necessary modifications, a meteorological model can play as a supporting tool for developing successful heat island mitigation strategies. This is further underlined through the operational character of the presented modeling system
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