410 research outputs found

    Object identification and characterization with hyperspectral imagery to identify structure and function of Natura 2000 habitats

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    Habitat monitoring of designated areas under the EU Habitats Directive requires every 6 years information on area, range, structure and function for the protected (Annex I) habitat types. First results from studies on heathland areas in Belgium and the Netherlands show that hyperspectral imagery can be an important source of information to assist the evaluation of the habitat conservation status. Hyperspectral imagery can provide continuous maps of habitat quality indicators (e.g., life forms or structure types, management activities, grass, shrub and tree encroachment) at the pixel level. At the same time, terrain managers, nature conservation agencies and national authorities responsible for the reporting to the EU are not directly interested in pixels, but rather in information at the level of vegetation patches, groups of patches or the protected site as a whole. Such local level information is needed for management purposes, e.g., exact location of patches of habitat types and the sizes and quality of these patches within a protected site. Site complexity determines not only the classification success of remote sensing imagery, but influences also the results of aggregation of information from the pixel to the site level. For all these reasons, it is important to identify and characterize the vegetation patches. This paper focuses on the use of segmentation techniques to identify relevant vegetation patches in combination with spectral mixture analysis of hyperspectral imagery from the Airborne Hyperspectral Scanner (AHS). Comparison with traditional vegetation maps shows that the habitat or vegetation patches can be identified by segmentation of hyperspectral imagery. This paper shows that spectral mixture analysis in combination with segmentation techniques on hyperspectral imagery can provide useful information on processes such as grass encroachment that determine the conservation status of Natura 2000 heathland areas to a large extent. A limitation is that both advanced remote sensing approaches and traditional field based vegetation surveys seem to cause over and underestimations of grass encroachment for specific categories, but the first provides a better basis for monitoring if specific species are not directly considered

    TESS unveils the phase curve of WASP-33b. Characterization of the planetary atmosphere and the pulsations from the star

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    We present the detection and characterization of the full-orbit phase curve and secondary eclipse of the ultra-hot Jupiter WASP-33b at optical wavelengths, along with the pulsation spectrum of the host star. We analyzed data collected by the Transiting Exoplanet Survey Satellite (TESS) in sector 18. WASP-33b belongs to a very short list of highly irradiated exoplanets that were discovered from the ground and were later visited by TESS. The host star of WASP-33b is of delta Scuti-type and shows nonradial pulsations in the millimagnitude regime, with periods comparable to the period of the primary transit. These completely deform the photometric light curve, which hinders our interpretations. By carrying out a detailed determination of the pulsation spectrum of the host star, we find 29 pulsation frequencies with a signal-to-noise ratio higher than 4. After cleaning the light curve from the stellar pulsations, we confidently report a secondary eclipse depth of 305.8 +/- 35.5 parts-per-million (ppm), along with an amplitude of the phase curve of 100.4 +/- 13.1 ppm and a corresponding westward offset between the region of maximum brightness and the substellar point of 28.7 +/- 7.1 degrees, making WASP-33b one of the few planets with such an offset found so far. Our derived Bond albedo, A_B = 0.369 +/- 0.050, and heat recirculation efficiency, epsilon = 0.189 +/- 0.014, confirm again that he behavior of WASP-33b is similar to that of other hot Jupiters, despite the high irradiation received from its host star. By connecting the amplitude of the phase curve to the primary transit and depths of the secondary eclipse, we determine that the day- and nightside brightness temperatures of WASP-33b are 3014 +/- 60 K and 1605 +/- 45 K, respectively. From the detection of photometric variations due to gravitational interactions, we estimate a planet mass of M_P = 2.81 +/- 0.53 M$_J.Comment: 19 pages, 15 figure

    Loss of AND-34/BCAR3 Expression in Mice Results in Rupture of the Adult Lens

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    PURPOSE. AND-34/BCAR3 (Breast Cancer Anti-Estrogen Resistance 3) associates with the focal adhesion adaptor protein, p130CAS/BCAR1. Expression of AND-34 regulates epithelial cell growth pattern, motility, and growth factor dependence. We sought to establish the effects of the loss of AND-34 expression in a mammalian organism. METHODS. AND-34−/− mice were generated by homologous recombination. Histopathology, in situ hybridization, and western blotting were performed on murine tissues. RESULTS. Western analyses confirmed total loss of expression in AND-34−/− splenic lymphocytes. Mice lacking AND-34 are fertile and have normal longevity. While AND-34 is widely expressed in wild type mice, histologic analysis of multiple organs in AND-34−/− mice is unremarkable and analyses of lymphocyte development show no overt changes. A small percentage of AND-34−/− mice show distinctive small white eye lesions resulting from the migration of ruptured cortical lens tissue into the anterior chamber. Following initial vacuolization and liquefaction of the lens cortex first observed at postnatal day three, posterior lens rupture occurs in all AND-34−/− mice, beginning as early as three weeks and seen in all mice at three months. Western blot analysis and in situ hybridization confirmed the presence of AND-34 RNA and protein in lens epithelial cells, particularly at the lens equator. Prior data link AND-34 expression to the activation of Akt signaling. While Akt Ser 473 phosphorylation was readily detectable in AND-34+/+ lens epithelial cells, it was markedly reduced in the AND-34−/− lens epithelium. Basal levels of p130Cas phosphorylation were higher in AND-34+/+ than in AND-34−/− lens epithelium. CONCLUSIONS. These results demonstrate the loss of AND-34 dysregulates focal adhesion complex signaling in lens epithelial cells and suggest that AND-34-mediated signaling is required for maintenance of the structural integrity of the adult ocular lens.National Institutes of Health (RO1 CA114094); Logica Foundatio

    Diagnostic stewardship based on patient profiles: differential approaches in acute versus chronic infectious syndromes

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    Introduction: New diagnostics may be useful in clinical practice, especially in contexts of high prevalence of multidrug-resistant organisms (MDRO). However, misuse of diagnostic tools may lead to increased costs and worse patient outcome. Conventional and new techniques should be appropriately positioned in diagnostic algorithms to guide an appropriate use of antimicrobial therapy. Areas covered: A panel of experts identified 4 main areas in which the implementation of diagnostic stewardship is needed. Among chronic infections, bone and prosthetic joint infections and subacute-chronic intravascular infections and endocarditis represent common challenges for clinicians. Among acute infections, bloodstream infections and community-acquired pneumonia may be associated with high mortality and require appropriate diagnostic approach. Expert opinion: Diagnostic stewardship aims to improve the appropriate use of microbiological diagnostics to guide therapeutic decisions through appropriate and timely diagnostic testing. Here, diagnostic algorithms based on different patient profiles are proposed for chronic and acute clinical syndromes. In each clinical scenario, combining conventional and new diagnostic techniques is crucial to make a rapid and accurate diagnosis and to guide the selection of antimicrobial therapy. Barriers related to the implementation of new rapid diagnostic tools, such as high initial costs, may be overcome through their rational and structured use
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