Cini A.,University Pierre and Marie Curie |
Cini A.,Italian Agricultural Research Council |
Anfora G.,Research and Innovation Center and Technology Transfer Center |
Escudero-Colomar L.A.,IRTA - Institute of Agricultural-Alimentary Research and Technology |
And 4 more authors.
Journal of Pest Science | Year: 2014
Biological invasions are a leading threat to native wildlife, human health and food production worldwide. Understanding the invasion history helps identifying introduction pathways and organizing integrated management strategies especially aimed at avoiding multiple reintroductions. We coupled a recently developed spatial analysis (Geographic profiling) with trade flows quantification to identify the most likely spreading centre of a recent invader of Europe, the spotted wing drosophila, Drosophila suzukii. This polyphagous vinegar fly recently colonized western countries, where it is heavily threatening fruit production causing severe economic losses. Characterized by a rapid spread and a huge impact, the invasion of this pest has a few precedents and it is becoming a model in invasion biology and pest management. Thanks to our spatial approach based on data presence of D. suzukii in European countries in the very first years of it spread, we update the current knowledge of a first spread in Spain and Italy, suggesting on the contrary that the South of France may be the most likely spreading centre of D. suzukii in Europe. Estimates of propagule pressure (fresh host fruits importation) support this finding as imports from contaminated South East Asian countries are higher in France than in Spain or Italy. Our study provides a first step in the comprehension of invasion history of this pest species and emphasizes geographic profiling as an efficient technique to track down invaders colonization patterns. © 2014, Springer-Verlag Berlin Heidelberg.
Santosuosso U.,Largo Brambilla |
Papini A.,University of Florence
International Journal of Environmental Science and Technology | Year: 2016
Geographic profiling is a method that proved to be useful also in order to investigate the point of origin of a biological invasion. K-means clustering and Voronoi diagrams can partition a data set of geographic positions of populations invading a defined area and are, therefore, useful in cases in which an invasion had more introduction events as points of origin. One critical point of the method is to identify the right number of clusters in which to divide the starting data set formed by groups of points on a map. The Silhouette method proved to be capable of identifying the best number of subsets (clusters) of the general set of observations by providing different values for different subdivisions of the set of observations in clusters. For each cluster, the corresponding Voronoi tessellation was built on the starting map. To test the method, we did a simulation of clusters of data (points) on a map and we verified whether the proposed methods worked efficiently with the simulated data set with hundred repeats and using a varying number of clusters on the same map. The used techniques revealed to be efficient in finding the highest probability area of the map that would include the starting points for each cluster. A case study consisted in a known data set, that is, the spreading pattern of Caulerpa racemosa var. cylindracea (sea grapes), that was compatible (highest probability) with an original point of introduction in southern Italy and long distance (thousands of kilometers) secondary spreads via anthropic dispersal. The proposed techniques may also be applied to other kinds of data sets of biological data distributed on a map or in general on a geometrical surface. © 2016, Islamic Azad University (IAU).
Lavorini F.,Largo Brambilla |
Magni C.,Largo Brambilla |
Chellini E.,Largo Brambilla |
Camiciottoli G.,Largo Brambilla |
And 2 more authors.
Respiratory Physiology and Neurobiology | Year: 2013
Respiratory responses to bronchoconstriction in asthma have been partially assessed and their significance is unclear. In 44 mild asthma patients we investigated respiratory responses during increasing levels of methacholine-induced bronchoconstriction. Inspiratory muscle activity, tidal volume, inspiratory and expiratory times were continuously monitored; breathing discomfort was rated. Mean inspiratory flow, respiratory frequency and ventilation were calculated. Lung function was assessed prior to and at maximum bronchoconstriction. Bronchoconstriction "dose-dependently" increased inspiratory muscle activity and breathing discomfort (P< 0.01). In 37 patients (84.1%), the increase in inspiratory muscle activity was associated with increases in mean inspiratory flow and ventilation (P< 0.01) because of selective rises in breathing depth (volume responders), or rate (frequency responders) or both (dual responders). In seven patients (15.9%) ventilation was unchanged. Individual respiratory responses were reproducible. With bronchoconstriction, frequency responders displayed greater hyperinflation and stronger breathing discomfort than volume responders (P< 0.01). Analysis of the responses to induced bronchoconstriction disclosed distinctive and reproducible respiratory adjustments that may identify functionally different asthma subpopulations. © 2013 Elsevier B.V.