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The contribution of roads to human economic and social development contrasts with its impact on the environment and wildlife. One of the most significant impacts of roads is wildlife-vehicle collisions. Millions of individuals from numerous species are killed annually around the world. Here we investigated the spatial and temporal dynamics of road killing on a small neotropical bird, the Blue-black Grassquit (Volatinia jacarina (Linnaeus, 1766)). We used a data set of roadkill records collected between 2010 and 2015 to test the hypotheses that roadkills are concentrated during the breeding period of the species and that road features and weather conditions affect the likelihood of animal-vehicle collisions. We observed that the number of fatalities was temporally and spatially clustered. Roadkills were more frequent in warmer, rainy days with lower wind speed. Fatalities were more commonly associated with two-lane roads compared with dirt and four-lane roads. Given that Blue-black Grassquits are attracted to human-modified habitats, especially to artificial grasslands composed of exotic grasses usually found along the margins of roads, mitigation measures should focus on the management and control of grass populations. Roadside mowing may reduce areas where Blue-black Grassquits can establish territories, and consequently, reduce the activity of the species near roads. Key words: bird-vehicle collision, Brazilian Cerrado, Blue-black Grassquit, edge effect, highways, road ecology, spatial clustering, Volatinia jacarina. La contribution des routes au developpement humain et social contraste avec leur incidence sur le milieu et les especes sauvages. Les collisions d'animaux sauvages et de vehicules representent l'un des impacts les plus importants des routes, tuant chaque annee des millions d'individus denombreuses especes partout dans le monde. Nous examinonsla dynamique spatiale et temporelle de la mortalite associee aux routes d'un petit oiseau neotropical, le jacarini noir (Volatinia jacarina (Linnaeus, 1766)). Nous utilisons un ensemble de donnees de morts d'individus sur des routes recueillies de 2010 a 2015 pour valider les hypotheses selon lesquelles les morts sur les routes se concentrent durant la saison de reproduction de l'espece et que des caracteristiques de la route et les conditions meteorologiques ont une incidence sur la probabilite de collision entre animaux et vehicules. Nous constatons que le nombre de collisions fatales est concentre dans le temps et dans l'espace. Les morts sont plus frequentes lors de jours chauds et pluvieux caracterises par de plus faibles vitesses du vent. Les morts sont plus souvent associees a des routes a deux voies qu'a des routes de terre ou des routes a quatre voies. Comme les jacarinis noirs sont attires par des habitats modifies par l'humain, en particulier par des prairies artificielles composees d'herbes exotiques generalement presentes le long des bordures de route, les mesures d'attenuation devraient s'axer sur la gestion et le controle des populations d'herbes. La tonte des bordures de route pourrait reduire les aires propices a l'etablissement de territoires de jacarinis noirs, et par consequent, l'activite de l'espece a proximite de routes. [Traduit par la Redaction] Mots-cles : collision oiseau-vehicule, Cerrado bresilien, jacarini noir, effet de bordure, routes, ecologie des routes, concentration spatiale, Volatinia jacarina., Introduction Human-induced modifications of habitat are a common process resulting from land occupation, intensifiedby population growth, and consequently, increased demand for resources (Ehrlich and Holdren 1971; Rippleet al. 2017). Recent [...]

Optimal design and sensitivity analysis of axisymmetric shells on the basis of a two-node frustum-cone finite element model is done. Optimal designing helps develop maximum natural frequency for minimum shell volume, with stresses, displacements and node shapes as some of the design variables. Symbolic manipulator and global finite difference are used for analytical and semianalytical design sensitivity calculation.