Use of faecal and stomach contents in assessing food niche relationships: a case study of two sympatric species of Podarcis lizards (sauria: lacertidae)

La niche trophique de deux espèces de lézards (Podarcis muralis et P. sicula) a été étudiée en analysant à la fois des contenus stomacaux et des pelotes fécales. Des comparaisons ont été conduites entre les deux espèces, portant sur leurs spectres trophiques, les largeurs et les recouvrements de leurs niches alimentaires. L'analyse fondée sur les contenus stomacaux a fourni les données les plus complètes et les plus détaillées. Podarcis sicula est apparu comme un prédateur plus généraliste que P muralis, le recouvrement de niche entre ces deux espèces étant très faible. Les données différentes qui existent dans la littérature, montrant un plus fort recouvrement, seraient dues à des préférences alimentaires locales et à l'utilisation de méthodes d'analyse différentes.The trophic niche of two sympatric species of wall lizards (Podarcis muralis and P. sicula) was studied by the analysis of both stomach contents and faecal pellets, and differences in trophic spectra, food niche breadth, and niche overlap were compared. The analysis based on stomach contents provided more complete and detailed data. Podarcis sicula appeared to be a more generalist predator than P. muralis, and the niche overlap between the two species was very Jow. Differences from literature data showing a higher overlap can be due to local food preferences and different methods of analysis

Definition and description of larval types of Cyaneolytta (Coleoptera Meloidae) and new records of their phoretic association with Carabidae (Coleoptera)

The hypothesis of a general phoretic association of Cyaneolytta Péringuey 1909 triungulins (Meloidae) with Anthiini (Carabidae) is supported by many new records from several regions of Africa and India. Four morphological larval types of Cyaneolytta are described and some morpho-species belonging to different morphotypes are identified and illustrated

Review of the genus Stenodera with a description of the first instar larva of S. puncticollis (Coleoptera: Meloidae)

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Activité alimentaire et utilisation de l’espace dans une population naturalisée de Myiopsitta monachus dans une zone urbaine méditerranéenne

We studied a naturalized population of monk parakeet breeding in an urban park in Rome, by collecting data on the diurnal and feeding activity, space use (e.g, roosting preferences, flight height) and behavioural traits (e.g., cluster size). Consideration on the potential ecological impact of the species is also made. The diurnal activity of parakeets did not differ between morning and afternoon. Most individuals were observed in flight 6-10 m from the ground, and when at roost, parakeets preferred perch es higher than 5 m. The clusters sighted on ground were significantly larger in size than those observed on roosts, while cluster size was not linked to flight height. For this species, the observed roost preference indicates that the availability of perches on high trees seems to be an important factor for habitat selection: standing on trees may increase the chances to identify trophic resources, reduce the risk of predation when at rest, and prevent overheating from high summer temperatures during the day. Regarding to feeding habits, at our study site the monk parakeet fed on different plant species both on the trees and at the ground level (e.g., Fabaceae, Ulmaceae, Poaceae, Rosaceae), showing a clear preference towards some plant species, irrespective to their abundance, and with Scolymus hispanicus (Asteraceae) as the most exploited species by farNous avons étudié une population naturalisée de la perruche Myiopsitta monachus dans un parc urbain de Rome en recueillant des données sur les activités diurnes et de recherche de nourriture, de même que l'utilisation de l'espace (e.g. préférences pour les reposoirs, hauteur de vol) et les traits comportementaux (e.g. taille des regroupements). L'impact écologique potentiel de l'espèce a également été pris en considération. L'activité diurne des perruches ne montre aucune différence entre le matin et l'après-midi. La plupart des individus volent 6-10 m au-dessus du sol et, aux reposoirs ils préfèrent des perchoirs situés à plus de 5 m de hauteur. Les groupes étaient significativement plus grands au sol que dans les reposoirs tandis que leur taille n'était pas liée à la hauteur de vol. Les préférences observées quant aux reposoirs indiquent que la disponibilité de perchoirs dans de hauts arbres est, pour cette espèce, un facteur important du choix de l'habitat: une remise dans les arbres peut accroître les chances d'identifier des sources de nourriture, réduire les risques de prédation au repos et protéger des fortes chaleurs quand les températures diurnes estivales sont très élevées. En matière d'habitudes alimentaires, dans notre site d'étude, cette perruche se nourrissait de diverses espèces végétales tant sur les arbres qu'au sol (e.g. Fabacées, Ulmacées, Poacées, Rosacées), montrant une nette préférence pour quelques espèces quelle que soit leur abondance, Scolymus hispanicus (Astéracées) étant de loin la plus exploitée

Comparaison des patrons d’abondance et de diversité des oiseaux cavitaires dans des habitats méditerranéens

Hole-nesting birds include species highly dependent on old trees or dead wood for nesting, roosting, breeding and feeding. In this study we characterize the assemblages of these species occurring in five different habitat types located in a heterogeneous Mediterranean landscape. We used the point count method. In all habitat types, tits (Parus major and Cyanistes caeruleus) were the most abundant species, except in beech forests, where Sitta europaea showed the highest mean abundance. Hole nesting bird assemblages increase in abundance, richness and diversity, with significant changes from termophilic and sclerophyllous forests (Holm-oak and Cork-oak) to temperate and mesophilic forests (chestnut, Turkey oak and Beech). This pattern reflects the progressive change in vegetation type both due to structure and species composition, ultimately due to progressive change in altitude and local climate. In particular, data at singles species level corroborate that the presence of mature and dead trees (i.e., with high mean diameter) may explain the abundance of Sitta europaea, Picus viridis and Certhia brachydactyla. Our dataset highlights that, for the hole-nesting birds, mesophilous beech and oak Mediterranean forests of biogeographic and conservation concern, represent suitable habitat types for these specialized speciesLes oiseaux cavitaires incluent des espèces très dépendantes des vieux arbres et des bois morts pour nicher, dormir et se nourrir. Dans la présente étude nous caractérisons les assemblages de ces espèces dans cinq types d'habitats différents situés dans un paysage méditerranéen hétérogène. Nous avons utilisé la méthode des points d'écoute. Dans tous les types d'habitats, les mésanges (Parus major et Cyanistes caeruleus) étaient les plus abondantes, sauf dans en hêtraie où Sitta europaea présentait la plus forte abondance moyenne. Les assemblages d'oiseaux cavitaires croissent en abondance, richesse et diversité, avec des changements significatifs, des forêts thermophiles et sclérophylles (Chêne vert et Chêne-liège) aux forêts tempérées er mésophiles (Châtaignier, Chêne turc et Hêtre). Ce patron reflète le changement progressif de la structure et de la composition spécifique des types de végétation en fonction de celui de l'altitude et du climat local. En particulier les données considérées au niveau spécifique confirment que la présence d'arbres matures et d'arbres morts (i.e. de gros diamètre) expliquerait l'abondance de Sitta europaea, Picus viridis et Certhia brachydactyla. Nos données soulignent combien, pour les oiseaux cavitaires, les forêts mésophiles méditerranéennes de hêtres et de chênes, importantes au plan biogéographique et à celui de la conservation, représentent de bons types d'habitats pour ces espèces spécialisées

Diffusion-weighted MRI radiomics of spine bone tumors: feature stability and machine learning-based classification performance

Purpose To evaluate stability and machine learning-based classification performance of radiomic features of spine bone tumors using diffusion- and T2-weighted magnetic resonance imaging (MRI). Material and methods This retrospective study included 101 patients with histology-proven spine bone tumor (22 benign; 38 primary malignant; 41 metastatic). All tumor volumes were manually segmented on morphologic T2-weighted sequences. The same region of interest (ROI) was used to perform radiomic analysis on ADC map. A total of 1702 radiomic features was considered. Feature stability was assessed through small geometrical transformations of the ROIs mimicking multiple manual delineations. Intraclass correlation coefficient (ICC) quantified feature stability. Feature selection consisted of stability-based (ICC > 0.75) and significance-based selections (ranking features by decreasing Mann-Whitney p-value). Class balancing was performed to oversample the minority (i.e., benign) class. Selected features were used to train and test a support vector machine (SVM) to discriminate benign from malignant spine tumors using tenfold cross-validation. Results A total of 76.4% radiomic features were stable. The quality metrics for the SVM were evaluated as a function of the number of selected features. The radiomic model with the best performance and the lowest number of features for classifying tumor types included 8 features. The metrics were 78% sensitivity, 68% specificity, 76% accuracy and AUC 0.78. Conclusion SVM classifiers based on radiomic features extracted from T2- and diffusion-weighted imaging with ADC map are promising for classification of spine bone tumors. Radiomic features of spine bone tumors show good reproducibility rates

Italian natural history museums on the verge of collapse?

The Italian natural history museums are facing a critical situation, due to the progressive loss of scientific relevance, decreasing economic investments, and scarcity of personnel. This is extremely alarming, especially for ensuring the long-term preservation of the precious collections they host. Moreover, a commitment in fieldwork to increase scientific collections and concurrent taxonomic research are rarely considered priorities, while most of the activities are addressed to public events with political payoffs, such as exhibits, didactic meetings, expositions, and talks. This is possibly due to the absence of a national museum that would have better steered research activities and overall concepts for collection management. We here propose that Italian natural history museums collaborate to instate a “metamuseum”, by establishing a reciprocal interaction network aimed at sharing budgetary and technical resources, which would assure better coordination of common long-term goals and scientific activities

3D vs. 2D MRI radiomics in skeletal Ewing sarcoma: Feature reproducibility and preliminary machine learning analysis on neoadjuvant chemotherapy response prediction

ObjectiveThe extent of response to neoadjuvant chemotherapy predicts survival in Ewing sarcoma. This study focuses on MRI radiomics of skeletal Ewing sarcoma and aims to investigate feature reproducibility and machine learning prediction of response to neoadjuvant chemotherapy. Materials and methodsThis retrospective study included thirty patients with biopsy-proven skeletal Ewing sarcoma, who were treated with neoadjuvant chemotherapy before surgery at two tertiary sarcoma centres. 7 patients were poor responders and 23 were good responders based on pathological assessment of the surgical specimen. On pre-treatment T1-weighted and T2-weighted MRI, 2D and 3D tumour segmentations were manually performed. Features were extracted from original and wavelet-transformed images. Feature reproducibility was assessed through small geometrical transformations of the regions of interest mimicking multiple manual delineations, and intraclass correlation coefficient >0.75 defined feature reproducibility. Feature selection also consisted of collinearity and significance analysis. After class balancing in the training cohort, three machine learning classifiers were trained and tested on unseen data using hold-out cross-validation. Results1303 (77%) 3D and 620 (65%) 2D radiomic features were reproducible. 4 3D and 4 2D features passed feature selection. Logistic regression built upon 3D features achieved the best performance with 85% accuracy (AUC=0.9) in predicting response to neoadjuvant chemotherapy. ConclusionCompared to 2D approach, 3D MRI radiomics of Ewing sarcoma had superior reproducibility and higher accuracy in predicting response to neoadjuvant chemotherapy, particularly when using logistic regression classifier