Delaunay Triangulation Algorithms Useful for Multibeam Echosounding

Brouns, Gert; Wulf, Alain De; Constales, Denis

doi:10.1061/(asce)0733-9453(2003)129:2(79)

Cited by 35 publications

(24 citation statements)

References 14 publications

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“…Because the samples were collected in a scattered arrangement, spatial analysis was adequate for visualizing genetic variation patterns throughout the study area and for identifying where genetic barriers may exist. Using geographic coordinates, a connectivity network among all sampling locations was constructed using Delaunay triangulation (Brouns, Wulf, & Constales, ), and the proportion of different nucleotides between individuals was used as genetic distance. This spatial interpolation was carried out with ais software (Miller, ) using the three concatenated mitochondrial genes.…”

Section: Methodsmentioning

confidence: 99%

Supporting the existence of two isolated evolutionary lineages ofGerres(Perciformes: Gerreidae) in America

et al. 2019

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For many years in America, many authors have considered that the Gerres genus contained a single species, the yellowfin mojarra Gerres cinereus (Walbaum, 1792); however, others have recognized two species in this genus in the Neotropics. In this study, specimens of G. cinereus (sensu lato) caught throughout its geographic range on both coasts of America were compared for the first time to analyse divergence among the sampled populations. A genetic analysis based on DNA sequences from three mitochondrial genes and one nuclear gene revealed a clear separation of two clades, one in the Pacific and one in the Atlantic. Geometric morphometric differences, based on body shape, sagittae otoliths and urohyal bone features, were significant between the two groups, including separation by an accurate classification a posteriori by a canonical variate analysis (CVA) > 82% in all data sets (overall mean >91%). Integration of the results of these approaches indicates that there is sufficient evidence to support species status for Gerres simillimus Regan, 1907, and it should be considered a valid species in the neotropical Pacific.

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Section: Methodsmentioning

confidence: 99%

Supporting the existence of two isolated evolutionary lineages ofGerres(Perciformes: Gerreidae) in America

et al. 2019

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“…The software ALLELES‐IN‐SPACE was used to visualize the spatial arrangement of genotypes within the sampled range and detect barriers to gene follow between sampled locations (Miller, 2005). Accordingly, a Delaunay triangulation (Brouns, De Wulf & Constales, 2003; Watson, 1992) was used to generate the connectivity network among collection sites. Thereafter, Monmonier's algorithm was employed to highlight geographical barriers between sampled locations, based on network edges associated with the highest rates of change between genotype and location (Manni, Guerard & Heyer, 2004).…”

Section: Methodsmentioning

confidence: 99%

Stay at home aphids: comparative spatial and seasonal metapopulation structure and dynamics of two specialist tansy aphid species studied using microsatellite markers

Loxdale

Schöfl

Wiesner

et al. 2011

Biological Journal of the Linnean Society

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Two tansy-feeding aphids, Macrosiphoniella tanacetaria (MA) and Metopeurum fuscoviride (ME), were studied at a small spatial scale in and around Jena (< 80 km 2 ) using polymorphic microsatellite markers. Both species were found in approximately 60% of sites formerly known to harbour the aphids, although, generally when they did occur, they occurred singly (MA~50%; ME~60%) and rarely together on the same plant at the same time (approximately 10%) and then usually only in the early part of the growing season. This difference may be a result of quasi-apparent competition effects elicited by ants farming ME aphids, and preferentially actively eliminating or disturbing MA aphids. In terms of population genetics, both aphids showed extreme genetic heterogeneity within a metapopulation structure, with ME more than MA (i.e. higher FST values, approximately 0.4 versus 0.15, respectively), and limited levels of interpopulation gene flow. Subpopulations often deviated from Hardy-Weinberg equilibrium and showed linkage disequilibria, as expected in animals with extended parthenogenetic reproduction, and had positive FIS values for most large samples, suggesting inbreeding, and possibly philopatry, certainly in ME. Hierarchical analysis (allele range and number per locus, analysis of molecular variance and FST) strongly suggested that the plant rather than site governs the level of genetic variation. Bayesian clustering analysis revealed that both species had heterogeneous historical genetic patterning, with K (number of subgroups) in the range 3-7. Evidence is also provided from isolation-by-distance and private allele analyses indicating that, in MA, the presence of winged autumn males, absent in ME where males are wingless, influences comparative population genetic structuring, such that ME subpopulations are comparatively more inbred and genetically differentiated than MA subpopulations. Lastly, additional spatial arrangement (ALLELES-IN-SPACE) analysis showed that, in both species, certain subpopulations were genetically isolated from the remainder, probably as a result of geographical barriers, including intervening buildings and woods. As such, the biology of these tansy aphids living in semi-natural habitats is very different from many pest aphid species examined within agro-ecosystems and infesting ephemeral crops. This is because the former appear to be much more reluctant to fly and hence show contrastingly much higher levels of interpopulation divergence, even at small spatial scales as investigated in the present study. Indeed, the number of genotypic clusters found for tansy aphids using Bayesian approaches is similar to that globally for the major pest, the peach-potato aphid, Myzus persicae.

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“…This is done by applying a Delaunay triangulation to create a spatial mesh for each object [15,16]. An example is given in Fig.…”

Section: B Derived Data Productsmentioning

confidence: 99%

Model inversion for midwater multibeam backscatter data analysis

et al. 2005

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Furthermore, various features can be tagged to each sounding, such as the backscatter energy value and some statistical parameters of the multibeam ping from which the sounding was obtained. The term data node is used to describe the sounding and its associated feature vector. The set of data nodes serves as the basis for further advanced spatio-temporal data mining techniques. Soundings can be clustered into coherent groups, each cluster representing an object in the water column, such as a fish school. Cluster features are obtained from the feature tags of their contained data nodes, giving rise to feature vectors for each cluster. Clusters can be classified into classes of different types, using each cluster's feature vector. When a cluster is thought of as a fish school, it can be classified according to fish species or age group, for example.The concept of a set of data nodes is a versatile concept that can be extended further, enabling the application of more advanced clustering and classification algorithms.

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Delaunay Triangulation Algorithms Useful for Multibeam Echosounding

Cited by 35 publications

References 14 publications

Supporting the existence of two isolated evolutionary lineages ofGerres(Perciformes: Gerreidae) in America

Supporting the existence of two isolated evolutionary lineages ofGerres(Perciformes: Gerreidae) in America

Stay at home aphids: comparative spatial and seasonal metapopulation structure and dynamics of two specialist tansy aphid species studied using microsatellite markers

Model inversion for midwater multibeam backscatter data analysis

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