Evaluation of river network generalization methods for preserving the drainage pattern

The drainage pattern of a river network is the arrangement in which a stream erodes the channels of its network of tributaries. It can reflect the geographical characteristics of a river network to a certain extent because it depends on the topography and geology of the land and as such should be considered during the river network generalization process. There are many methods for river network generalization in tributary selection but most do not explicitly consider the network pattern. Validation of the generalized result is performed visually by an expert and may not be done systematically. An automatic validation technique may help to better understand the results obtained with each method and check whether the pattern has been preserved. This paper proposes an approach to evaluate the quality of a generalized river network by assessing how well its original drainage pattern is preserved. The membership to a drainage pattern is evaluated by a set of geometric indicators, making use of a fuzzy logic approach which allows for a compromise between different criteria depending on the membership values. Three tributary selection methods are tested in this work: selection by stroke and length, catchment area, and a manually generalized network. Assessing the quality of a generalization is done by comparing pattern memberships before and after generalization. This research provides a quantitative indicator to assess the generalized river network in preserving geographical information

An ontology for the generalisation of the bathymetry on nautical charts

On nautical charts, undersea features are portrayed by sets of soundings (depth points) and isobaths (depth contours) from which map readers can interpret landforms. Different techniques were developed for automatic soundings selection and isobath generalisation from a sounding set. These methods are mainly used to generate a new chart from the bathymetric database or from a large scale chart through selection and simplification however a part of the process consists in selecting and emphasising undersea features on the chart according to their relevance to navigation. Its automation requires classification of the features from the set of isobaths and soundings and their generalisation through the selection and application of a set of operators according not only to geometrical constraints but also to semantic constraints. The objective of this paper is to define an ontology formalising undersea feature representation and the generalisation process achieving this representation on a nautical chart. The ontology is built in two parts addressing on one hand the definition of the features and on the other hand their generalisation. The central concept is the undersea feature around which other concepts are organised. The generalisation process is driven by the features where the objective is to select or emphasise information according to their meaning for a specific purpose. The ontologies were developed in Protégé and a bathymetric database server integrating the ontology was implemented. A generalisation platform was also developed and examples of representations obtained by the platform are presented. Finally, current results and on-going research are discussed

Species Diversity and Phylogenetic Relationships of Olive Lace Bugs (Hemiptera: Tingidae) Found in South Africa

SIMPLE SUMMARY: Olive lace bugs feed on wild and cultivated Olea europaea, causing a negative impact on plant vitality and development. These insects are known to affect olive orchards in South Africa, the country where most of the olive and olive products on the continent are produced. However, the diversity of species of these pests is not clear. Morphological analysis and DNA barcoding showed the presence of Cysteochila lineata, Plerochila australis, Neoplerochila paliatseasi and Neoplerochila sp. Further analyses of genetic divergence and phylogenetic clustering in 30 species in 18 genera of Tingidae using new and publicly available DNA barcodes showed that the majority of sequences deposited on BOLD Systems were correctly assigned to species. The complete mitochondrial genomes of the four species found in South Africa were sequenced to assess their phylogenetic position within Tingidae. The four olive lace bugs formed one cluster of species, and the genus Cysteochila was not monophyletic as C. lineata grouped with the other three olive lace bugs but C. chiniana was placed in a different cluster. This result suggests that lace bug species that feed on olive trees may have a common ancestor and calls for further research on potential adaptations to O. europaea. ABSTRACT: Olive lace bugs (Hemiptera: Tingidae) are small sap-sucking insects that feed on wild and cultivated Olea europaea. The diversity of olive lace bug species in South Africa, the most important olive producer on the continent, has been incompletely surveyed. Adult specimens were collected in the Western Cape province for morphological and DNA-based species identification, and sequencing of complete mitogenomes. Cysteochila lineata, Plerochila australis, Neoplerochila paliatseasi and Neoplerochila sp. were found at 12 sites. Intra- and interspecific genetic divergences and phylogenetic clustering in 30 species in 18 genera of Tingidae using new and publicly available DNA barcodes showed high levels of congruity between taxonomic and genetic data. The phylogenetic position of the four species found in South Africa was inferred using new and available mitogenomes of Tingidae. Notably, olive lace bugs formed a cluster of closely related species. However, Cysteochila was non-monophyletic as C. lineata was recovered as a sister species to P. australis whereas Cysteochila chiniana, the other representative of the genus, was grouped with Trachypeplus jacobsoni and Tingis cardui in a different cluster. This result suggests that feeding on O. europaea may have a common origin in Tingidae and warrants future research on potential evolutionary adaptations of olive lace bugs to this plant host

Soluble markers of B cell activation suggest a role of B cells in the pathogenesis of systemic sclerosis-associated pulmonary arterial hypertension

IntroductionSoluble markers of B cell activation are interesting diagnostic and prognostic tools in autoimmune diseases. Data in systemic sclerosis (SSc) are scarce and few studies focused on their association with disease characteristics.Methods1. Serum levels of 14 B cell biomarkers (β2-microglobulin, rheumatoid factor (RF), immunoglobulins (Ig) G, IgA, IgM, BAFF, APRIL, soluble (s)TACI, sBCMA sCD21, sCD23, sCD25, sCD27, CXCL13) were measured in SSc patients and healthy controls (HC). 2. Associations between these biomarkers and SSc characteristics were assessed. 3. The pathophysiological relevance of identified associations was explored by studying protein production in B cell culture supernatant.ResultsIn a discovery panel of 80 SSc patients encompassing the broad spectrum of disease manifestations, we observed a higher frequency of RF positivity, and increased levels of β2-microglobulin, IgG and CXCL13 compared with HC. We found significant associations between several biomarkers and SSc characteristics related to disease phenotype, activity and severity. Especially, serum IgG levels were associated with pulmonary hypertension (PH); β2-microglobulin with Nt-pro-BNP and DLCO; and BAFF with peak tricuspid regurgitation velocity (TRV). In a validation cohort of limited cutaneous SSc patients without extensive ILD, we observed lower serum IgG levels, and higher β2-microglobulin, sBCMA, sCD23 and sCD27 levels in patients with pulmonary arterial hypertension (PAH). BAFF levels strongly correlated with Nt-pro-BNP levels, FVC/DLCO ratio and peak TRV in SSc-PAH patients. Cultured SSc B cells showed increased production of various angiogenic factors (angiogenin, angiopoietin-1, VEGFR-1, PDGF-AA, MMP-8, TIMP-1, L-selectin) and decreased production of angiopoietin-2 compared to HC.ConclusionSoluble markers of B cell activation could be relevant tools to assess organ involvements, activity and severity in SSc. Their associations with PAH could plead for a role of B cell activation in the pathogenesis of pulmonary microangiopathy. B cells may contribute to SSc vasculopathy through production of angiogenic mediators

Nouveaux Tingidae de Nouvelle-Calédonie (Hemiptera, Heteroptera)

After canopy samples of four New-Caledonian primary forests, done in 1992-1993 by fogging, two new species (Physatocheila dissimilis sp. n. et Tingis chazeaui sp. n.) of Tingidae are described and a new combination for Physatocheila irregularis Montrouzier 1861 is proposed.Suite à des échantillonnages effectués par thermonébulisation (fogging), en 1992-1993, dans la canopée de quatre forêts primaires néocalédoniennes, deux nouvelles espèces (Physatocheila dissimilis n. sp. et Tingis chazeaui n. sp.) de Tingidae sont décrites et une nouvelle combinaison pour Physatocheila irregularis Montrouzier 1861 est proposée.Guilbert Éric. Nouveaux Tingidae de Nouvelle-Calédonie (Hemiptera, Heteroptera). In: Bulletin de la Société entomologique de France, volume 102 (3), août 1997. pp. 293-298

Nouveaux Tingidae de Nouvelle-Calédonie (Hemiptera, Heteroptera)

After canopy samples of four New-Caledonian primary forests, done in 1992-1993 by fogging, two new species (Physatocheila dissimilis sp. n. et Tingis chazeaui sp. n.) of Tingidae are described and a new combination for Physatocheila irregularis Montrouzier 1861 is proposed.Suite à des échantillonnages effectués par thermonébulisation (fogging), en 1992-1993, dans la canopée de quatre forêts primaires néocalédoniennes, deux nouvelles espèces (Physatocheila dissimilis n. sp. et Tingis chazeaui n. sp.) de Tingidae sont décrites et une nouvelle combinaison pour Physatocheila irregularis Montrouzier 1861 est proposée.Guilbert Éric. Nouveaux Tingidae de Nouvelle-Calédonie (Hemiptera, Heteroptera). In: Bulletin de la Société entomologique de France, volume 102 (3), août 1997. pp. 293-298

Two new species of <i>Dicysta</i> (Hemiptera, Tingidae) from New Caledonia

Dans ce travail, nous décrivons deux nouvelles espèces de Nouvelle-Calédonie appartenant au genre Dicysta Champion. Il s\u27agit de la première mention du genre pour cette île. Les deux espèces se trouvent en forêt dense humide, dans deux sites de composition botanique différente.Two new species belonging to the genus Dicysta Champion are described from New Caledonia, being the first record of this genus in the island. Both species were found in dense evergreen forest, in two patches differing in their botanical composition.</p

Morphologie et évolution des excroissances larvaires de Tingidae (Insecta,Heteroptera), avec description de nouvelles larves

Dans le cadre de l’étude de l’évolution des Tingidae (Insecta, Heteroptera), la morphologie des larves de cinquième stade de 13 espèces est analysée, au travers de leur description, à savoir Amblystira peltogyne, Aristobyrsa uaupenensis, Atheas insignis, Corythauma ayyari, Corythucha mcelfreshi, Dictyla rasilis, Idiocysta dryadis, Kapiriella maynei, Leptopharsa gibbicarina, Orotingis eueides, Urenthius vepris, Phatnoma marmorata, Eocader vergrandis. Les larves portent des excroissances sur la face dorsale, caractères qui leur sont propres. Une description et une classification de la disparité de ces excroissances, séparées en deux principales catégories, sont proposées. Ces excroissances sont supposées nouvelles dans le cadre de l’évolution des Tingidae et un scénario évolutif de la morphologie des excroissances est proposé. Les espèces avec des larves sans excroissances sont plus plésiomorphiques et celles avec excroissances ont évolué à partir de ces dernières. Ces excroissances, d’abord simples, sont devenues complexes à travers l’évolution.In the frame of the study of the evolution of Tingidae (Heteroptera), the morphological structure of fifth instars of 13 species is analysed here, through their description, namely Amblystira peltogyne, Aristobyrsa uaupenensis, Atheas insignis, Corythauma ayyari, Corythucha mcelfreshi, Dictyla rasilis, Idiocysta dryadis, Kapiriella maynei, Leptopharsa gibbicarina, Orotingis eueides, Urenthius vepris, Phatnoma marmorata, Eocader vergrandis. Larvae exhibit outgrowths on the dorsum, which are proper characters. A description and classification of the wide range of outgrowth shapes separated in two main categories is provided. These outgrowths are hypothesized as apomorphic in the framework of the evolution of Tingidae, and an evolutionary scenario of outgrowth morphology is attempted. Species with larvae without outgrowth are more plesiomorphic, and those with outgrowths evolved from the former. Their outgrowths, first simple, became complex during the evolution.</p

A Segmentation Approach to Identify Underwater Dunes from Digital Bathymetric Models

The recognition of underwater dunes has a central role to ensure safe navigation. Indeed, the presence of these dynamic landforms on the seafloor represents a hazard for navigation, especially in navigation channels, and should be at least highlighted to avoid collision with vessels. This paper proposes a novel method dedicated to the segmentation of these landforms in the fluvio-marine context. Its originality relies on the use of a conceptual model in which dunes are characterized by three salient features, namely the crest line, the stoss trough, and the lee trough. The proposed segmentation implements the conceptual model by considering the DBM (digital bathymetric model) as the seafloor surface from which the dunes shall be segmented. A geomorphometric analysis of the seabed is conducted to identify the salient features of the dunes. It is followed by an OBIA (object-based image analysis) approach aiming to eliminate the pixel-based analysis of the seabed surface, forming objects to better describe the dunes present in the seafloor. To validate the segmentation method, more than 850 dunes were segmented in the fluvio-marine context of the Northern Traverse of the Saint-Lawrence river. A performance rate of nearly 92% of well segmented dunes (i.e., true positive) was achieved

An Approach for the Automatic Characterization of Underwater Dunes in Fluviomarine Context

The identification of underwater landforms represents an important role in the study of the seafloor morphology. In this context, the segmentation and characterization of underwater dunes allow a better understanding of the dynamism of the seafloor, since the formation of these structures is directly related to environmental conditions, such as current, tide, grain size, etc. In addition, it helps to ensure safe navigation, especially in the context of navigation channels requiring periodic maintenance. This paper proposes a novel method to automatically characterize the underwater dunes. Its originality relies on the extraction of morphological descriptors not only related to the dune itself, but also to the fields where the dunes are located. Furthermore, the proposed approach involves the entire surface of the dunes, rather than profiles or group of pixels as generally found in previous works. Considering the surface modelled by a digital bathymetric model (DBM), the salient features of the dunes (i.e., crest line, stoss trough, and lee trough) are first identified using a geomorphometric analysis of the DBM. The individual dunes are built by matching the crest lines with their respective troughs according to an object-oriented approach. Then, a series of morphological descriptors, selected through a literature review, are computed by taking advantage of the dune salient features, surface representation, and spatial distribution in the fields where they are located. The validation of the proposed method has been conducted using more than 1200 dunes in the fluvio-marine context of the Northern Traverse of the Saint Lawrence River