183 research outputs found

    Seed germination reports of high mountain species native to Mount Etna (Sicily)

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    The germination ability of five endemic species from the high mountain belt of Mt. Etna were studied; they are Astragalus siculus, Erysimum etnense, Senecio squalidus subsp. aethnensis, Silene italica subsp. sicula, and Tanacetum vulgare subsp. siculum. Mature seeds were collected in the field, within an elevation range of 1700–2000 m a.s.l. Different experimental conditions were tested and the best methods with optimal germination results are provided and compared for each species. First germination records are given for 4 out of 5 of the investigated taxa

    Denoising and enhancement of mammographic images under the assumption of heteroscedastic additive noise by an optimal subband thresholding

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    Mammographic images suffer from low contrast and signal dependent noise, and a very small size of tumoral signs is not easily detected, especially for an early diagnosis of breast cancer. In this context, many methods proposed in literature fail for lack of generality. In particular, too weak assumptions on the noise model, e.g., stationary normal additive noise, and an inaccurate choice of the wavelet family that is applied, can lead to an information loss, noise emphasizing, unacceptable enhancement results, or in turn an unwanted distortion of the original image aspect. In this paper, we consider an optimal wavelet thresholding, in the context of Discrete Dyadic Wavelet Transforms, by directly relating all the parameters involved in both denoising and contrast enhancement to signal dependent noise variance (estimated by a robust algorithm) and to the size of cancer signs. Moreover, by performing a reconstruction from a zero-approximation in conjunction with a Gaussian smoothing filter, we are able to extract the background and the foreground of the image separately, as to compute suitable contrast improvement indexes. The whole procedure will be tested on high resolution X-ray mammographic images and compared with other techniques. Anyway, the visual assessment of the results by an expert radiologist will be also considered as a subjective evaluation

    Problematicità tassonomiche e corologiche nel genere Fraxinus (Oleaceae) in Italia.

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    Il contributo analizza le criticità tassonomiche e la distribuzione sul territorio italiano delle specie del genere Fraxinus, evidenziando la necessità di una revisione tassonomica e nomenclaturale dei taxa esistent

    Noise estimation in cardiac x-ray imaging: a machine vision approach

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    YesWe propose a method to automatically parameterize noise in cardiac x-ray image sequences. The aim was to provide context-sensitive imaging information for use in regulating dose control feedback systems that relates to the experience of human observers. The algorithm locates and measures noise contained in areas of approximately equal signal level. A single noise metric is derived from the dominant noise components based on their magnitude and spatial location in relation to clinically relevant structures. The output of the algorithm was compared to noise and clinical acceptability ratings from 28 observers viewing 40 different cardiac x-ray imaging sequences. Results show good agreement and that the algorithm has the potential to augment existing control strategies to deliver x-ray dose to the patient on an individual basis.This work has been performed in the project PANORAMA, funded by grants 335 from Belgium, Italy, France, the Netherlands, United Kingdom, and the ENIAC Joint Undertaking

    Aggiornamenti e novità sulle conoscenze di Pancratium maritimum (Amaryllidaceae)

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    Pancratium maritimum L., bulbosa perenne degli ambienti dunali costieri, è un taxon relativamente recente se comparato con le specie del genere a gravitazione mediterranea. Gli studi noti su questa specie hanno analizzato vari aspetti della biologia (riproduttivi, biochimici, filogenetici, genetici, ecc.). Tuttavia, esistono ancora lacune scientifiche, tra cui l’assenza di studi su ampio areale di genetica di conservazione e sugli adattamenti eco-morfofisiologici alle condizioni di stress. Per ampliare le conoscenze su P. maritimum, la Fondazione Nando Peretti nel novembre 2012 ha finanziato un progetto triennale sulla conoscenza e la salvaguardia di questa specie (Progetto 2012-83). In questo contributo si presentano i risultati ottenuti per le diverse linee di ricerca finora affrontate, che vanno dalle analisi ad ampio areale dei popolamenti, usando un approccio sia genetico che GIS, alla caratterizzazione morfologica e eco-fisiologica di varie popolazioni

    The RIBES strategy for ex situ conservation: conventional and modern techniques for seed conservation

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    The Italian seed bank network (RIBES) aims to improve the quality and safety of the germplasm reserves of native plant species in Italy to ensure the long-term conservation of endangered and/or endemic flora. The strategy includes traditional methods to secure seed conservation. A comprehensive priority list for seed collection is being defined, it was prepared by crossing data of various checklists (red lists, endemics) and will soon be cross-referenced with an updated list of accessions of the whole network. A safety-backup program of duplicates will quickly be implemented to secure the conservation of the most threatened species in at least two seed banks of the network. On the other hand, the RIBES strategy also includes research by applying modern techniques. In collaboration with the Millennium Seed Bank, research on the storage behaviour of seeds and spores through thermal analysis is ongoing to inform conservation. Using the Differential Scanning Calorimetry (DSC), we could evaluate seed lipid properties such as glass transition temperature, melting, crystallization, oxidation behaviour, and thermal stability. Finally, RIBES participates as a co-funder in the LIFE Nature project SEEDFORCE, coordinating 11 seed banks of the network for collecting seeds/spores of 29 threatened species of EU interest

    The RIBES strategy for ex situ conservation: conventional and modern techniques for seed conservation

    Get PDF
    The Italian seed bank network (RIBES) aims to improve the quality and safety of the germplasm reserves of native plant species in Italy to ensure the long-term conservation of endangered and/or endemic flora. The strategy includes traditional methods to secure seed conservation. A comprehensive priority list for seed collection is being defined, it was prepared by crossing data of various checklists (red lists, endemics) and will soon be cross-referenced with an updated list of accessions of the whole network. A safety-backup program of duplicates will quickly be implemented to secure the conservation of the most threatened species in at least two seed banks of the network. On the other hand, the RIBES strategy also includes research by applying modern techniques. In collaboration with the Millennium Seed Bank, research on the storage behaviour of seeds and spores through thermal analysis is ongoing to inform conservation. Using the Differential Scanning Calorimetry (DSC), we could evaluate seed lipid properties such as glass transition temperature, melting, crystallization, oxidation behaviour, and thermal stability. Finally, RIBES participates as a co-funder in the LIFE Nature project SEEDFORCE, coordinating 11 seed banks of the network for collecting seeds/spores of 29 threatened species of EU interest

    Reference ranges of uterine arteries pulsatility index from first to third trimester based on serial Doppler measurements: longitudinal cohort study

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    Objective: To provide gestational age (GA)-specific reference ranges for uterine artery (UtA) mean pulsatility index (PI) based on longitudinal data assessment throughout pregnancy. Methods: This was a prospective longitudinal cohort study of singleton low-risk pregnancies with adequate health and nutritional status at the time of enrollment and without any fetal anomaly, receiving prenatal care from January 2018 to July 2021 at the Maternal Fetal Medicine Unit of IRCSS San Raffaele Scientific Institute, Milan. Women were recruited at ≤ 12+6 weeks' gestation and then underwent serial standardized ultrasound monitoring including UtA-PI measurements, by experienced certified operators until delivery. A modulus exponential normal (MEN) model smoothed with fractional polynomial was implemented to model UtA-PI as a function of GA. Equations for mean (μ) and standard deviation (SD) of the estimated curves were calculated as well as GA-specific reference charts of centiles for UtA-PI from 10+0 to 39+0 gestational weeks. Results: 476 healthy, low-risk pregnant women were included. A total of 2045 ultrasound scans were available for analysis. For all the included women at least 3 measures were recorded (observations per woman: median 4, range 3-9). At the three trimesters, the mean±SD UtA-PI values were equal to 1.84 +/-0.55, 1.07 +/-0.38 and 0.78+/- 0.23 respectively. Goodness of fit assessment revealed that second-degree smoothing was the most accurate fractional polynomial for describing UtA-PI course throughout gestation; therefore, it was modelled in a multilevel framework for the construction of UtA-PI curves. There was a rapid and significant decrease in the mean UtA-PI before 16 weeks, then the slope decreased with smoother decrement and more stable values from 20 up until 39 weeks. The 3rd , 5th , 10th , 25th , 50th , 75th , 90th , 95th and 97th centiles according to GA for UtA-PI are provided, as well as equations to allow calculation of any value as a centile. Conclusions: UtA-PI shows a progressive non-linear decrease throughout pregnancy. The new reference ranges for GA-specific UtA-PI constructed with rigorous methodology may have a better impact than previous models for screening placenta-associated diseases in the early stages of pregnancy and yet also for evaluating patients at later potential risk for pregnancy-induced hypertension and/or small for gestational age fetuses. This article is protected by copyright. All rights reserved
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