60 research outputs found

    Human disturbances and predation on artificial ground nests across an urban gradient

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    Perturbaciones antropogénicas y depredación en nidos artificiales en el suelo en un gradiente urbano En nuestro estudio con nidos artificiales observamos que la ausencia de especies de aves que nidifican en el suelo en el centro urbano y en barrios residenciales se debía a las molestias causadas por personas y animales domésticos (perros y gatos) y no a la depredación. Además, la presión por depredación fue superior en la periferia de la ciudad debido al mayor número de depredadores naturales. Nuestros resultados sugieren que la planificación y creación de zonas protegidas podrían aumentar la posibilidad de que las aves que nidifican en el suelo se establecieran y se reprodujeran en paisajes dominados por los humanos.Perturbaciones antropogénicas y depredación en nidos artificiales en el suelo en un gradiente urbano En nuestro estudio con nidos artificiales observamos que la ausencia de especies de aves que nidifican en el suelo en el centro urbano y en barrios residenciales se debía a las molestias causadas por personas y animales domésticos (perros y gatos) y no a la depredación. Además, la presión por depredación fue superior en la periferia de la ciudad debido al mayor número de depredadores naturales. Nuestros resultados sugieren que la planificación y creación de zonas protegidas podrían aumentar la posibilidad de que las aves que nidifican en el suelo se establecieran y se reprodujeran en paisajes dominados por los humanos.In our study with artificial nests we observed that the absence of ground nesting bird species in the city centre and in residential districts was due to disturbance by humans and domestic animals (dogs and cats) rather than to predation. Furthermore, predation pressure was higher in the outskirts of the city due to the greater number of natural predators. Our results suggest that planning and creating undisturbed areas could increase the chances of ground nesting birds settling and breeding in human–dominated landscapes

    Vegetation-based landscape regions of Hungary.

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    he first version of the map of the Hungarian vegetation-based landscape regions were prepared at the scale of 1 : 200,000 (1 km or higher resolution). The primary goal of the map was to provide an exact background for the presentation and evaluation of the data of theMÉTA database. Secondly, we intended to give an up-to-date and detailed vegetation-based division of Hungary with a comprehensive nomenclature of the regions. Regions were primarily defined on the basis of their present zonal vegetation, or their dominant extrazonal or edaphic vegetation. Where this was not possible, abiotic factors that influence the potential vegetation, the flora were taken into consideration, thus, political and economical factors were ignored. All region borders were defined by local expert botanists, mainly based on their field knowledge. The map differs in many features from the currently used, country- wide, flora- or geography-based divisions in many features. We consider our map to be temporary (i.e. a work map), and we plan to refine and improve it after 5 years of testing

    Influence of contact points on the performance of caries detection methods in approximal surfaces of primary molars: an in vivo study

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    This in vivo study aimed to evaluate the influence of contact points on the approximal caries detection in primary molars, by comparing the performance of the DIAGNOdent pen and visual-tactile examination after tooth separation to bitewing radiography (BW). A total of 112 children were examined and 33 children were selected. In three periods (a, b, and c), 209 approximal surfaces were examined: (a) examiner 1 performed visual-tactile examination using the Nyvad criteria (EX1); examiner 2 used DIAGNOdent pen (LF1) and took BW; (b) 1 week later, after tooth separation, examiner 1 performed the second visual-tactile examination (EX2) and examiner 2 used DIAGNOdent again (LF2); (c) after tooth exfoliation, surfaces were directly examined using DIAGNOdent (LF3). Teeth were examined by computed microtomography as a reference standard. Analyses were based on diagnostic thresholds: D1: D 0 = health, D 1 –D 4 = disease; D2: D 0 , D 1 = health, D 2 –D 4 = disease; D3: D 0 –D 2 = health, D 3 , D 4 = disease. At D1, the highest sensitivity/specificity were observed for EX1 (1.00)/LF3 (0.68), respectively. At D2, the highest sensitivity/ specificity were observed for LF3 (0.69)/BW (1.00), respectively. At D3, the highest sensitivity/specificity were observed for LF3 (0.78)/EX1, EX2 and BW (1.00). EX1 showed higher accuracy values than LF1, and EX2 showed similar values to LF2. We concluded that the visual-tactile examination showed better results in detecting sound surfaces and approximal caries lesions without tooth separation. However, the effectiveness of approximal caries lesion detection of both methods was increased by the absence of contact points. Therefore, regardless of the method of detection, orthodontic separating elastics should be used as a complementary tool for the diagnosis of approximal noncavitated lesions in primary molars

    The Seventh Data Release of the Sloan Digital Sky Survey

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    This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

    Contrast in Edge Vegetation Structure Modifies the Predation Risk of Natural Ground Nests in an Agricultural Landscape

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    Nest predation risk generally increases nearer forest-field edges in agricultural landscapes. However, few studies test whether differences in edge contrast (i.e. hard versus soft edges based on vegetation structure and height) affect edge-related predation patterns and if such patterns are related to changes in nest conspicuousness between incubation and nestling feeding. Using data on 923 nesting attempts we analyse factors influencing nest predation risk at different edge types in an agricultural landscape of a ground-cavity breeding bird species, the Northern Wheatear (Oenanthe oenanthe). As for many other bird species, nest predation is a major determinant of reproductive success in this migratory passerine. Nest predation risk was higher closer to woodland and crop field edges, but only when these were hard edges in terms of ground vegetation structure (clear contrast between tall vs short ground vegetation). No such edge effect was observed at soft edges where adjacent habitats had tall ground vegetation (crop, ungrazed grassland). This edge effect on nest predation risk was evident during the incubation stage but not the nestling feeding stage. Since wheatear nests are depredated by ground-living animals our results demonstrate: (i) that edge effects depend on edge contrast, (ii) that edge-related nest predation patterns vary across the breeding period probably resulting from changes in parental activity at the nest between the incubation and nestling feeding stage. Edge effects should be put in the context of the nest predator community as illustrated by the elevated nest predation risk at hard but not soft habitat edges when an edge is defined in terms of ground vegetation. These results thus can potentially explain previously observed variations in edge-related nest predation risk

    New national and regional bryophyte records, 52

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    Marchantia paleacea is a new species for the Umbria Region and is rare in central and southern Italy. This record is in a Site of Community Importance (SCI) IT5220017 and a Special Area of Conservation (SAC) of the Natura 2000 EU-wide network due to the presence of the 7220* ‘Petrifying springs with tufa formation (Cratoneurion)’ Annexe I priority habitat. The particular environment, with a gorge and waterfall, created a very special microclimate that allowed the establishment of interesting liverworts and mosses
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