Chain Homotopies for Object Topological Representations

This paper presents a set of tools to compute topological information of simplicial complexes, tools that are applicable to extract topological information from digital pictures. A simplicial complex is encoded in a (non-unique) algebraic-topological format called AM-model. An AM-model for a given object K is determined by a concrete chain homotopy and it provides, in particular, integer (co)homology generators of K and representative (co)cycles of these generators. An algorithm for computing an AM-model and the cohomological invariant HB1 (derived from the rank of the cohomology ring) with integer coefficients for a finite simplicial complex in any dimension is designed here. A concept of generators which are "nicely" representative cycles is also presented. Moreover, we extend the definition of AM-models to 3D binary digital images and we design algorithms to update the AM-model information after voxel set operations (union, intersection, difference and inverse)

An accurate density functional theory for the vaporliquid interface of chain molecules based on the statistical associating fluid theory for potentials of variable range for Mie chainlike fluids

A new Helmholtz free energy density functional is presented to predict the vapor-liquid interface of chainlike molecules. The functional is based on the last version of the statistical associating fluid theory for potentials of variable range for homogeneous Mie chainlike fluids (SAFT-VR Mie). Following the standard formalism, the density functional theory (SAFT-VR Mie DFT) is constructed using a perturbative approach in which the free energy density contains a reference term to describe all the short-range interactions treated at the local level, and a perturbative contribution to account for the attractive perturbation which incorporates the long-range dispersive interactions. In this first work, we use a mean-field version of the theory in which the pair correlations are neglected in the attractive term. The SAFT-VR Mie DFT formalism is used to examine the effect of molecular chain length and the repulsive exponent of the intermolecular potential on density profiles and surface tension of linear chains made up to six Mie (lr6) segments with different values of the repulsive exponent of the intermolecular potential. Theoretical predictions from the theory are compared directly with molecular simulation data for density profiles and surface tension of Mie chainlike molecules taken from the literature. Agreement between theory and simulation data is good for short-chain molecules at all thermodynamic conditions of coexistence considered. Once the theory has proven that is able to predict the interfacial properties, and particularly interfacial tension, the SAFT-VR Mie DFT formalism is used to predict the interfacial behavior of two new coarse-grained models for carbon dioxide and water recently proposed in the literature. In particular, the theoretical formalism, in combination with the coarse-grained models for carbon dioxide and water, is able to predict the interfacial properties of these important substances in a reasonable way.The authors thank helpful discussions with Carlos Avendaño andJosé Matías Garrido. We also acknowledge Centro de Supercom-putación de Galicia (CESGA, Santiago de Compostela, Spain) andMCIA (Mésocentre de Calcul Intensif Aquitain) of the Universitésde Bordeaux and Pau et Pays de l’Adour (France), for providingaccess to computing facilities and Ministerio de Economía, In-dustria y Competitividad through Grant with reference FIS2017-89361-C3-1-P co-financed by EU FEDER funds. Further financialsupport from Junta de Andalucía and Universidad de Huelva isalso acknowledged. J.A., J.M.M., and F.J.B. thankfully acknowl-edge the computer resources at Magerit and the technical supportprovided by the Spanish Supercomputing Network (RES) (ProjectQCM-2018-2-0042)

Método para la detección, identificación y cuantificación de Peronospora arborescens por PCR cuantitativa en tiempo real

Método para la detección, identificación y cuantificación de Peronospora arborescens por PCR cuantitativa en tiempo real. El método para la cuantificación de Peronospora arborescens por PCR cuantitativa (qPCR) en una muestra biológica, comprende extraer el ADN contenido en dicha muestra biológica y amplificarlo mediante qPCR. De aplicación en la cuantificación de P. arborescens.Peer reviewedConsejo Superior de Investigaciones Científicas (España), ALCALIBER SA, Universidad de CórdobaA1 Solicitud de patentes con informe sobre el estado de la técnic

Combined use of a new SNP-based assay and multilocus SSR markers to assess genetic diversity of Xylella fastidiosa subsp. pauca infecting citrus and coffee plants

Two haplotypes of Xylella fastidiosa subsp. pauca (Xfp) that correlated with their host of origin were identified in a collection of 90 isolates infecting citrus and coffee plants in Brazil, based on a single-nucleotide polymorphism in the gyrB sequence. A new single-nucleotide primer extension (SNuPE) protocol was designed for rapid identification of Xfp according to the host source. The protocol proved to be robust for the prediction of the Xfp host source in blind tests using DNA from cultures of the bacterium, infected plants, and insect vectors allowed to feed on Xfp-infected citrus plants. AMOVA and STRUCTURE analyses of microsatellite data separated most Xfp populations on the basis of their host source, indicating that they were genetically distinct. The combined use of the SNaPshot protocol and three previously developed multilocus SSR markers showed that two haplotypes and distinct isolates of Xfp infect citrus and coffee in Brazil and that multiple, genetically different isolates can be present in a single orchard or infect a single tree. This combined approach will be very useful in studies of the epidemiology of Xfp-induced diseases, host specificity of bacterial genotypes, the occurrence of Xfp host jumping, vector feeding habits, etc., in economically important cultivated plants or weed host reservoirs of Xfp in Brazil and elsewhere [Int Microbiol 2015; 18(1):13-24]Keywords: Citrus variegated chlorosis · coffee leaf scorch · vector transmission· xylem-limited bacteria · haplotype characterization · host-plant associatio

Las Especies sudamericanas del género "Neralsia" Cameron, 1883 (Hymenoptera: Cynipoidea: Figitidae: Figitinae): estudio del material tipo

Les espècies sud-americanes del gènere Neralsia Cameron, 1883 (Hymenoptera: Cynipoidea: Figitidae: Figitinae): estudi del material tipus Neralsia Cameron, 1883, és un gènere de distribució americana present tant a la regió neàrtica com neotropical. Aquest treball és la primera contribució taxonòmica que fem del gènere. Fa referència a l'estudi de les 12 espècies descrites de Neralsia a Sud-amèrica. Neralsia fiebrigi Hedicke, 1914, N. ciliatinervis (Kieffer, 1910) i N. acuminata (Dettmer, 1932) han de ser considerades com incertae sedis. S'estableix la sinonímia entre N. splendens (Borgmeier, 1935) i N. fossulata (Kieffer, 1909). Es transfereix Xyalophora albipennis Kieffer, 1909, al gènere Neralsia, N. albipennis (Kieffer, 1909) n. comb. Per tot això, es consideren vàlides vuit espècies: N. albipennis (Kieffer, 1909), N. bogotensis (Kieffer, 1909), N. claripennis (Dettmer, 1932), N. fossulata (Kieffer, 1909), N. flavidipennis (Kieffer, 1909), N. pilosa (Borgmeier, 1935), N. striaticeps (Kieffer, 1909) i N. suffecta (Dettmer, 1932). Es redescriuen aquestes espècies ja que les descripcions dels autors anteriors presenten, en general, deficiències diagnòstiques.Neralsia Cameron, 1883, es un género de distribución americana presente tanto en la región neártica como neotropical. Este trabajo es la primera contribución taxonómica que realizamos del género. Se refiere al estudio de las 12 especies descritas de Neralsia en Sudamérica. Neralsia fiebrigi Hedicke, 1914, N. ciliatinervis (Kieffer, 1910) y N. acuminata (Dettmer, 1932) han de ser consideradas como incertae sedis. Se establece la sinonimia entre N. splendens (Borgmeier, 1935) y N. fossulata (Kieffer, 1909). Se transfiere Xyalophora albipennis Kieffer, 1909, al género Neralsia, N. albipennis (Kieffer, 1909) n. comb. Por todo ello, se consideran válidas ocho especies: N. albipennis (Kieffer, 1909), N. bogotensis (Kieffer, 1909), N. claripennis (Dettmer, 1932), N. fossulata (Kieffer, 1909), N. flavidipennis (Kieffer, 1909), N. pilosa (Borgmeier, 1935), N. striaticeps (Kieffer, 1909) y N. suffecta (Dettmer, 1932). Se redescriben dichas especies puesto que las descripciones de los autores anteriores presentan, por lo general, deficiencias diagnósticas.The South American species of the genus Neralsia Cameron, 1883 (Hymenoptera: Cynipoidea: Figitidae: Figitinae): a study of the type material The genus Neralsia Cameron, 1883, has an American distribution and it is present in both Neotropical and Nearctic regions. The present work is our first contribution to the taxonomy of this genus and deals with the 12 species of Neralsia described from South America. Of these, Neralsia fiebrigi Hedicke, 1914, Neralsia ciliatinervis (Kieffer, 1910) and Neralsia acuminata (Dettmer, 1932) have to be considered «incertae sedis». The synonymy of Neralsia splendens (Borgmeier, 1935) and N. fossulata (Kieffer, 1909) is established. The species Xyalophora albipennis Kieffer, 1909, is transferred to Neralsia as N. albipennis (Kieffer, 1909) n. comb. In conclusion, 8 of the 12 previously known species are considered valid: N. albipennis (Kieffer, 1909), N. bogotensis (Kieffer, 1909), N. claripennis (Dettmer, 1932), N. fossulata (Kieffer, 1909), N. flavidipennis (Kieffer, 1909), N. pilosa (Borgmeier, 1935), N. striaticeps (Kieffer, 1909) and N. suffecta (Dettmer, 1932). These species are redescribed here because the original descriptions generally have diagnostic deficiencies

Combined use of a new SNP-based assay and multilocus SSR markers to assess genetic diversity of Xylella fastidiosa subsp. pauca infecting citrus and coffee plants

Two haplotypes of Xylella fastidiosa subsp. pauca (Xfp) that correlated with their host of origin were identified in a collection of 90 isolates infecting citrus and coffee plants in Brazil, based on a single-nucleotide polymorphism in the gyrB sequence. A new single-nucleotide primer extension (SNuPE) protocol was designed for rapid identification of Xfp according to the host source. The protocol proved to be robust for the prediction of the Xfp host source in blind tests using DNA from cultures of the bacterium, infected plants, and insect vectors allowed to feed on Xfp- infected citrus plants. AMOVA and STRUCTURE analyses of microsatellite data separated most Xfp populations on the basis of their host source, indicating that they were genetically distinct. The combined use of the SNaPshot protocol and three previously developed multilocus SSR markers showed that two haplotypes and distinct isolates of Xfp infect citrus and coffee in Brazil and that multiple, genetically different isolates can be present in a single orchard or infect a single tree. This combined approach will be very useful in studies of the epidemiology of Xfp- induced diseases, host specificity of bacterial genotypes, the occurrence of Xfp host jumping, vector feeding habits, etc., in economically important cultivated plants or weed host reservoirs of Xfp in Brazil and elsewhere [Int Microbiol 2015; 18(1):13-24].We acknowledge financial support from the EU grant ICA4-CT-2001-10005 and an ‘Intramural Project’ to B. B. Landa from the Spanish National Research Council (CSIC), as well as CNPq for a scholarship to J. R. S. Lopes in Brazil.Peer reviewe

First report of Meloidogyne arenaria parasitizing lettuce in southern Spain

During the 2005-2006 autumn to winter lettuce-growing (Lactuca sativa cv. Iceberg) season, severely stunted and yellowing lettuce plants with disease incidence ranging from 80 to 100% were observed in four commercial, fall-sown fields at Almodóvar del Río (Córdoba Province) in southern Spain. Early symptoms consisted of severely reduced growth of the plants that continued with extensive leaf yellowing and the absence of tight-head formation. Attacks by the disease were estimated to cause near complete loss of the crop yields since the lettuce head produced in affected fields were unmarketable. Observations of affected lettuce plants revealed high parasitism of the root system by a root-knot nematode (Meloidogyne sp.) in the main and feeder roots as well as heavy soil infestations by the nematode. The nematode was identified by the female perineal pattern, esterases phenotype, and a sequence-characterized amplified region polymerase chain reaction (SCAR-PCR) technique. Measurements and morphological observations of 20 second-stage juveniles (J2s) (body length = 463 ± 28 μm, dorsal gland orifice from stylet base = 2.8 ± 0.6 μm, stylet length = 10.4 ± 0.5 μm, tail length = 54.4 ± 0.6 μm; hyaline tail terminus = 9.4 ± 0.6 μm) and 10 adult females (stylet length = 14.5 ± 0.7 μm, dorsal gland orifice from stylet base = 4.7 ± 0.5 μm, and perineal pattern with low and rounded dorsal arch with coarse striae) conformed to the description of Meloidogyne arenaria. On the basis of the characteristics of the perineal pattern, the 2-band esterase phenotype, and the 420-bp SCAR fragment, the causal agent was identified as the peanut root-knot nematode M. arenaria. Nematodes were extracted from soil and root samples by standard procedures and their populations quantified. M. arenaria was detected in nearly all soil and root samples assessed, with nematode population densities ranging from 206 to 1,072 eggs and J2s per 5 g of fresh roots. Different Meloidogyne spp. have been reported parasitizing lettuce roots, especially M. hapla in northern areas (2); however, to our knowledge this is the first time that M. arenaria is reported parasitizing lettuce roots in Spain and elsewhere.Peer reviewe