1,182 research outputs found

    Automatic image characterization of psoriasis lesions

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    Psoriasis is a chronic skin disease that affects 125 million people worldwide and, par-ticularly, 2% of the Spanish population, characterized by the appearance of skin lesions due to a growth of the epidermis that is seven times larger than usual. Its diagnosis and monitoring are based on the use of methodologies for measuring the severity and extent of these spots, and this includes a large subjective component. For this reason, this paper presents an automatic method for characterizing psoriasis images that is divided into four parts: image preparation or pre-processing, feature extraction, classification of the lesions, and the obtaining of parameters. The methodology proposed in this work covers different digital-image processing techniques, namely, marker-based image delimitation, hair removal, nipple detection, lesion contour detection, areal-measurement-based lesion classification, as well as lesion characterization by means of red and white intensity. The results obtained were also endorsed by a professional dermatologist. This methodology provides professionals with a common software tool for monitoring the different existing typologies, which proved satisfactory in the cases analyzed for a set of 20 images corresponding to different types of lesions

    Biological control of Acanthoscelides obtectus and Zabrotes subfasciatus in stored dried beans

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    This study assesses the feasibility of using natural enemies for the control of Acanthoscelides obtectus Say and Zabrotes subfasciatus Boheman (Coleoptera: Chrysomelidae), key pests of stored dried beans, Phaseolus vulgaris L. (Fabales: Fabaceae). The predatory mites Blattisocius tarsalis Berlese (Acari: Ascidae) and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) were able to prey on A. obtectus eggs, reducing the bruchid population by more than 60% under both controlled and warehouse conditions. Therefore, they show good potential as biological agents for controlling this pest. The larval parasitoids Anisopteromalus calandrae Howard and Lariophagus distinguendus Förster (Hymenoptera: Pteromalidae) were both moderately effective (34–38% reduction) at suppressing A. obtectus populations, but when A. calandrae was combined with B. tarsalis, a significant improvement in control efficacy (81% reduction in emergence) was observed. Therefore, the release of A. calandrae combined with B. tarsalis seems to be a promising strategy for controlling A. obtectus. Neither B. tarsalis nor A. swirskii were able to prey on Z. subfasciatus eggs. Only the parasitoid A. calandrae was moderately effective (39% reduction) at supressing Z. subfasciatus populations. Further testing is needed to identify other natural enemies that can complement the action of A. calandrae in reducing Z. subfasciatus populations.info:eu-repo/semantics/acceptedVersio

    Noncommutative effective LQC: A (pre-)inflationary dynamics investigation

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    We conduct a (pre-)inflationary dynamics study within the framework of a simple noncommutative extension of effective loop quantum cosmology -- put forward recently by the authors -- which preserves its key features (in particular, the quantum bounce is maintained). A thorough investigation shows that the (pre-)inflationary scenario associated to the chaotic quadratic potential is in the overall the same as the one featured in standard loop quantum cosmology (which reinforces the conclusion reached by the authors in a preliminary analysis). Hence, this (pre-)inflationary scenario does not easily distinguish between standard loop quantum cosmology and the aforementioned noncommutative scheme. It is argued that a particular tuning of the noncommutativity parameter could accommodate for subtle effects at the level of primordial perturbations (the hybrid quantization framework being a tentative route of analysis).Comment: 22 pages, 18 figures, 1 tabl

    Susceptibility of Rhyzopertha dominica to high CO2 modified atmospheres in packaged chickpeas

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    Three MAs with 50%, 70% and 90% CO2 in air was tested at different exposure times on all the developmental stages of R. dominica using chickpeas packed with 4% and 96% filling ratio in which there was excess of CO2. At 4% filling ratio the loss of the gas was negligible. The exposure time to reach 50% mortality (LT50) was estimated for each developmental stage and CO2 concentration, ranging from 7 h for larvae with 90% to 2 days for pupae with 50% CO2. At 96% filling ratio and for the intervals of the estimated exposure times (LT50) from the 4% filling ratio, mortality decreased significantly for eggs and adults at the three MAs tested, while for the internal developmental stages, larvae at 50% and 70% CO2 and pupae in all concentrations of CO2, the susceptibility remained the same as with a 4% filling ratio. This decline in mortality of the external developmental stages was possible due to the sorption of CO2 by the chickpeas, which caused a loss of intergranular levels of CO2 between 17% and 29%. This sorption ranged from 0.1955 to 0.3285 g of CO2 per kg of chickpeas and produced a negative pressure of 77.12 to 60.65 kPa. In conclusion, when chickpeas are packed with high CO2 MAs, a decrease in the mortality of eggs and adults of R. dominica could be expected due to pulse sorption.info:eu-repo/semantics/acceptedVersio

    Growth of Northwest Iberian juvenile hake estimated by combining sagittal and transversal otolith microstructure analyses

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    Este es un artículo aceptado para publicación en Fisheries Research siguiendo revisión por pares. La versión definitiva puede consultarse en la web del editorDaily growth of Atlantic juvenile hake from Northwest Iberia has been estimated employing a new approach combining analyses of transversal and sagittal sections of the otoliths along the ventral radius. Age of juvenile hake ranging from 3 to 25 cm collected during a spring 2002 survey was estimated. Somatic growth followed a power fit: Fish size (TL) = 3.3254*age0.7336 (r2 = 0.87, p < 0.001, n = 76), yielding an average individual growth rate of 0.66 mm/day (±0.06). The growth model indicates that after a year's life a juvenile can reach 25 cm. Otolith ventral radius ranged from 401 to 1842 μm and daily increments were between 104 and 387. Fish growth and otolith growth were closely related (r2 = 0.92 p < 0.001, n = 76). These first results of daily growth rates for the Southern stock corroborate the fast-growth hypothesis of this species. The evolution of increment widths from hatch dates onwards reveals important seasonal growth peaks during July–August and October–November. A comparison with prior data and discussion is also presented in the light of recent work on hake juveniles and tagging-recapture experiences
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