779 research outputs found

    Evolutionary and demographic correlates of Pleistocene coastline changes in the Sicilian wall lizard Podarcis wagleriana

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    Aim Emergence of coastal lowlands during Pleistocene ice ages might have provided conditions for glacial expansions (demographic and spatial), rather than contraction, of coastal populations of temperate species. Here, we tested these predictions in the insular endemic Sicilian wall lizard Podarcis wagleriana. Location Sicily and neighbouring islands. Methods We sampled 179 individuals from 45 localities across the whole range of P. wagleriana. We investigated demographic and spatial variations through time using Bayesian coalescent models (Bayesian phylogeographic reconstruction, Extended Bayesian Skyline plots, Isolation‐with‐migration models) based on multilocus DNA sequence data. We used species distribution modelling to reconstruct present and past habitat suitability. Results We found two main lineages distributed in the east and west portions of the current species range and a third lineage restricted to a small area in the north of Sicily. Multiple lines of evidence from palaeogeographic (shorelines), palaeoclimatic (species distribution models), and multilocus genetic data (demographic and spatial Bayesian reconstructions) indicate that these lineages originated in distinct refugia, located in the north‐western and south‐eastern coastal lowlands, during Middle Pleistocene interglacial phases, and came into secondary contact following demographic and spatial expansions during the last glacial phase. Main conclusions This scenario of interglacial contraction and glacial expansion is in sharp contrast with patterns commonly observed in temperate species on the continent but parallels recent findings on other Mediterranean island endemics. Such a reverse expansion–contraction (EC) dynamic has been likely associated with glacial increases of climatically suitable coastal lowlands, suggesting this might be a general pattern in Mediterranean island species and also in other coastal regions strongly affected by glacial marine regressions during glacial episodes. This study provides explicit predictions and some methodological recommendations for testing the reverse EC model in other region and taxa

    All-for-One and One-For-All: Deep learning-based feature fusion for Synthetic Speech Detection

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    Recent advances in deep learning and computer vision have made the synthesis and counterfeiting of multimedia content more accessible than ever, leading to possible threats and dangers from malicious users. In the audio field, we are witnessing the growth of speech deepfake generation techniques, which solicit the development of synthetic speech detection algorithms to counter possible mischievous uses such as frauds or identity thefts. In this paper, we consider three different feature sets proposed in the literature for the synthetic speech detection task and present a model that fuses them, achieving overall better performances with respect to the state-of-the-art solutions. The system was tested on different scenarios and datasets to prove its robustness to anti-forensic attacks and its generalization capabilities.Comment: Accepted at ECML-PKDD 2023 Workshop "Deep Learning and Multimedia Forensics. Combating fake media and misinformation

    Evolutionary history of the Maltese wall lizard Podarcis filfolensis : insights on the 'expansion-contraction' model of Pleistocene biogeography

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    The expansion-contraction (EC) model predicts demographic and range contraction of temperate species during Pleistocene glaciations as a consequence of climate-related habitat changes, and provides a paradigm for explaining the high intraspecific diversity found in refugia in terms of long-term demographic stability. However, recent evidence has revealed a weak predictive power of this model for terrestrial species in insular and coastal settings. We investigated the Pleistocene EC dynamics and their evolutionary consequences on temperate species using the Maltese archipelago and its endemic lizard Podarcis filfolensis as a model system. The evolutionary and demographic history of P. filfolensis as inferred from mitochondrial and nuclear sequences data does not conform to the EC model predictions, supporting (i) demographic and spatial stability or expansion, rather than contraction, of the northern and southern lineages during the last glacial period; and (ii) a major role for allopatric differentiation primed by sea-level dynamics, rather than prolonged demographic stability, in the formation of the observed genetic diversity. When combined with evidence from other Mediterranean refugia, this study shows how the incorporation of Pleistocene sea-level variations in the EC model accounts for a reverse demographic and range response of insular and coastal temperate biotas relative to continental ones. Furthermore, this cross-archipelago pattern in which allopatric diversity is formed and shaped by EC cycles resembles that seen between isolated populations within mainland refugia and suggests that the EC model, originally developed to explain population fluctuations into and out-of refugia, may be appropriate for describing the demographic and evolutionary dynamics driving the high genetic diversity observed in these areas.peer-reviewe

    Effect of biofilm removal from the occlusal tooth surfaces on fluorescence measurements. A clinical study

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    Aim: Early diagnosis and monitoring of caries lesions are the most important issues of primary and secondary prevention policies.The intraoral VistaCamiX(DurrDental, Bietigheim‐Bissingen,Germany) uses the fluorescence phenomenon for a non‐invasive, quantitative caries diagnosis. In order to make a precise evaluation the tooth surface must be completely cleaned and without biofilm. The current study aimed to evaluate the effects of biofilm removal, using air‐polishing device (Combi,MectronSpA) with glycine, on fluorescence VistaCam iX camera quantitative measurements of caries. Methods: Patients with complete permanent dentition without any kind of restorative treatments in the lateral and posterior section of upper and lower dental arches were enrolled. The occlusal surfaces of molars and premolars were photographed using the fluorescence terminal Proof of the intraoral camera VistaCam iX before and after air polishing glycine procedures, registering the highest value gained for each occlusal surface. Results:133cuspidate permanent teeth of patients aged between 13 and 25 were analyzed. Descriptive analysis showed an average of 0.82 (SD=0.65; Min=0.00; Max=1.80; Median=1.20) and of 0.93 (SD=0.60; Min=0.00; Max=1.70; Median=1.20) for values before and after treatment, respectively.The scores assigned by VistaCam iX Proof fluorescence based camera to the occlusal surfaces, after the air‐polishing treatment, are averagely higher than those before treatment, especially in the diagnosis of initial tooth decay. Conclusion: Biofilm removal with glycine air‐polishing improves the VistaCam camera accuracy in recognizing healthy tissue from the decayed one, due to the fact that air-polishing treatment increases the decayed tissue reaction to the fluorescence

    Predicting elusiveness: potential distribution model of the Southern smooth snake, Coronella girondica, in Italy

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    Predictive models of species distribution may be very useful for understanding actual distribution of elusive species, including several snakes. The southern smooth snake (Coronella girondica) is likely the most elusive snake species of peninsular Italy, and is therefore well-suited for predicting potential distribution studies. In this paper we predict the potential distribution map of this species in Italy by using MAXENT algorithm, that finds the probability distribution of maximum entropy that is constrained by considered ecological parameters. Presence data for Coronella girondica were gotten from CKmap. The potential distribution model of Coronella girondica showed a very good overall performance (AUC = 0.959), and indicated that high suitability areas correspond mainly to Tyrrhenian north and central regions, including Liguria, western Emilia-Romagna, Tuscany, Umbria, and northern Latium. Southern Italian regions were clearly unsuitable for this snake species. Overall, our study revealed that previous distribution maps indicating the occurrence of Coronella girondica in southern Italy and Sicily were poorly reliable. The conservation and management implications of our study are also addressed
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