Search results for "Satellite"
showing 10 items of 1031 documents
Comparison of Radiosonde and Remote Sensing Data to Evaluate Convective Forest Fire Risk: The Haines Index
2018
Haines Index (HI) has been associated with convective forest fires risk. Temperatures and humidities in low atmospheric levels are required to compute HI and usually, atmospheric sounding data are used for this purpose. However, spatial and temporal resolutions of these data are coarse and remote sensing data could improve them. Therefore, the aim of this work is to test remote sensing data from the Atmospheric Infrared Sounder (AIRS) instrument on board the EOS Aqua satellite, specifically the Level 2 V6 products (AIRX2RET and AIRS2RET), for this purpose. First, we validated the remote sensing data with radiosonde daytime and nighttime data located in the Iberian Peninsula in 2014. Signifi…
A new system for animal products traceability and authentication: Use of DNA analysis of natural tracers and example of application to dry cured hams
2010
A few DNA based approaches have been developed to trace animal products from the farm to the consumer “fork”. These approaches make use of the animal DNA that can be recovered during all steps of t...
Conservation of genetic diversity in artificially regenerated holm oak (Quercus ilex L.) populations
2004
Reforestation with autochtonous species should take into account the preservation of the variability and the geographical structure of genetic diversity in forest species. In order to provide empirical data, genetic composition of an artificial population of holm oak (Quercus ilex L.) and its natural seed-origin population in Andalusia were analysed with six microsatellite loci. The genetic diversity indices applied show a reduction in the artificial stand if compared with the natural one, probably due to an inappropriate forester seed collection strategy limited to a few trees.
Autocorrelation Metrics to Estimate Soil Moisture Persistence From Satellite Time Series: Application to Semiarid Regions
2021
Satellite-derived soil moisture (SM) products have become an important information source for the study of land surface processes in hydrology and land monitoring. Characterizing and estimating soil memory and persistence from satellite observations is of paramount relevance, and has deep implications in ecology, water management, and climate modeling. In this work, we address the problem of SM persistence estimation from microwave sensors using several autocorrelation metrics that, unlike traditional approaches, build on accurate estimates of the autocorrelation function from nonuniformly sampled time series. We show how the choice of the autocorrelation estimator can have a dramatic impac…
The marbled crayfish as a paradigm for saltational speciation by autopolyploidy and parthenogenesis in animals
2015
ABSTRACT The parthenogenetic all-female marbled crayfish is a novel research model and potent invader of freshwater ecosystems. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax, but its taxonomic status has remained unsettled. By cross-breeding experiments and parentage analysis we show here that marbled crayfish and P. fallax are reproductively separated. Both crayfish copulate readily, suggesting that the reproductive barrier is set at the cytogenetic rather than the behavioural level. Analysis of complete mitochondrial genomes of marbled crayfish from laboratory lineages and wild populations demonstrates genetic identity and indicates a single o…
Landsat TM/ETM+ and tree-ring based assessment of spatiotemporal patterns of the autumnal moth (Epirrita autumnata) in northernmost Fennoscandia
2010
Abstract We used fine-spatial resolution remotely sensed data combined with tree-ring parameters in order to assess and reconstruct disturbances in mountain birch ( Betula pubescens ) forests caused by Epirrita autumnata (autumnal moth). Research was conducted in the area of Lake Tornetrask in northern Sweden where we utilized five proxy parameters to detect insect outbreak events over the 19th and 20th centuries. Digital change detection was applied on three pairs of multi-temporal NDVI images from Landsat TM/ETM+ to detect significant reductions in the photosynthetic activity of forested areas during disturbed growing seasons. An image segmentation gap-fill procedure was developed in orde…
B1 Was the Ancestor B Chromosome Variant in the Western Mediterranean Area in the Grasshopper Eyprepocnemis plorans.
2014
We analyzed the distribution of 2 repetitive DNAs, i.e. ribosomal DNA (rDNA) and a satellite DNA (satDNA), on the B chromosomes found in 17 natural populations of the grasshopper Eyprepocnemis plorans plorans sampled around the western Mediterranean region, including the Iberian Peninsula, Balearic Islands, Sicily, and Tunisia. Based on the amount of these repetitive DNAs, 4 types of B variants were found: B 1 , showing an equal or higher amount of rDNA than satDNA, and 3 other variants, B 2 , B 24 and B 5 , bearing a higher amount of satDNA than rDNA. The variants B 1 and B 2 varied in size among populations: B 1 was about half the size of the X chromosome in Balearic Islands, but two-thir…
Space-VLBI phase-reference mapping and astrometry
2001
We present 5 GHz space-VLBI observations of the quasar pair B1342+662/B1342+663 that demonstrate the feasibility of phase-reference techniques using an antenna in space. The space-based data were taken by the satellite HALCA, of the space-VLBI mission VSOP. From residual (referenced) phases we derive an upper bound of 10 meters to the uncertainty of the spacecraft orbit reconstruction. An analysis of the phase-reference maps of the sources additionally suggests that the above mentioned uncertaintyis likely not larger than 3 meters. With errors of this magnitude, HALCA is a useful tool for astrometric studies of close pairs of radio sources.
Direct detection of repetitive, whole chromosome paint and telomere DNA probes by immunogold electron microscopy
1993
Biotinylated repetitive, whole chromosome paint and telomere DNA probes were investigated at the electron microscope level after non-isotopic in situ hybridization and direct immunogold detection. The protocol described allowed the visualization of a biotinylated chromosome 1 specific satellite DNA probe in the light microscope without silver intensification. This sensitive method was exploited to analyse factors contributing to signal strength in immunogold chromosome painting. Furthermore, it allowed us to investigate the distribution of (TTAGGG)n telomere repeats in human metaphase chromosomes and interphase nuclei. Telomeric and internal (TTAGGG)n repeats were detected at high spatial r…
Aplicación del Estimador de Parámetros de Segmentación por Media-desplazada (EPSM) a las imágenes de satélite de muy alta resolución espacial: Tetuán…
2015
<p>La segmentación de imágenes constituye un paso crucial en el Análisis de Imágenes Basado en Objetos (AIBO). Combinando distintos valores de los parámetros de entrada de los algoritmos de segmentación se obtienen diferentes resultados. En general, los parámetros óptimos seleccionados se determinan mediante interpretación visual; por lo tanto, la definición de las combinaciones óptimas es una tarea considerablemente difícil. En la presente investigación, se propone una herramienta analítica que denominamos Estimador de Parámetros de Segmentación por Media-desplazada (EPSM) aplicada a la selección automatizada de los valores de los parámetros de segmentación en las imágenes de satélit…