199 research outputs found

    First record of Curius chemsaki Nearns and Ray, 2006 (Coleoptera: Cerambycidae: Cerambycinae: Curiini) in Colombia

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    Curius chemsaki Nearns and Ray, 2006 (Coleoptera: Cerambycidae: Cerambycinae: Curiini), is reported from Colombia for the first time. In addition, the range of this taxon within Venezuela is extended to the Andean Province of Táchira

    Long time behaviour of the solution of Maxwell's equations in dissipative generalized Lorentz materials (II) A modal approach

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    This work concerns the analysis of electromagnetic dispersive media modelled by generalized Lorentz models. More precisely, this paper is the second of two articles dedicated to the long time behaviour of solutions of Maxwell's equations in dissipative Lorentz media, via the long time decay rate of the electromagnetic energy for the corresponding Cauchy problem. In opposition to the frequency dependent Lyapunov functions approach used in [Cassier, Joly, Rosas Mart\'inez, Z. Angew. Math. Phys. 74 (2023), 115], we develop a method based on the spectral analysis of the underlying non-self-adjoint operator of the model. Although more involved, this approach is closer to physics, as it uses the dispersion relation of the model, and has the advantage to provide more precise and more optimal results, leading to distinguish the notion of weak and strong dissipation.Comment: 67 pages, 4 figure

    Una nueva especie de Cyclocephala Latreille de la Amazonia Venezolana (Coleoptera, Scarabaeidae, Dynastinae, Cyclocephalini)

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    JOLY LJ. 2005. A new species of Cyclocephala Latreille from the Venezuelan Amazonia (Coleoptera, Scarabaeidae, Dynastinae, Cyclocephalini). Entomotropica 20(1): 1-5. Cyclocephala divaricata sp. n. is described from the Venezuelan Amazonia; the structure of mouth parts, male anterior claw and aedeagus, together with the dark body colour differentiate it from all other species in the genus. Characters distinguishing the new species from C. munda and C. nodanotherwon are given, and diagnostic characters are illustrated.JOLY LJ. 2005. Una nueva especie de Cyclocephala Latreille de la Amazonia Venezolana (Coleoptera, Scarabaeidae, Dynastinae, Cyclocephalini). Entomotropica 20(1): 1-5. Se describe Cyclocephala divaricata sp. n., del Amazonia Venezolana; la estructura de las piezas bucales, la u\uf1a anterior del macho, el aedeago y el color oscuro del cuerpo la diferencian de todas las otras especies del g\ue9nero. Se mencionan los caracteres que la diferencian de C. munda Kirsch, 1870 y de C. nodanotherwon Ratcliffe 1992 y se ilustran los caracteres diagn\uf3sticos

    Larval morphology of Meruidae (Coleoptera: Adephaga) and its phylogenetic implications

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    This is the publisher's version, also available electronically from http://www.ingentaconnect.com/content/esa/aesa. This article is the copyright property of the Entomological Society of America and may not be used for any commercial or other private purpose without specific written permission of the Entomological Society of AmericaMeruidae, or comb-clawed cascade beetles, are a recently discovered monotypic family of Adephaga endemic to Venezuela. The larvae of Meruidae are described for the first time, based on material of Meru phyllisae Spangler & Steiner, 2005, collected together with adults in southern Venezuela. External morphological features, including chaetotaxy, are reported for the mature larva and an assessment made of the polarity of larval characters of phylogenetic utility in Adephaga. Larvae of Meruidae possess a mixture of primitive and derived character states, and they are unique within the Adephaga in that here the mandibles are asymmetrical, the respiratory system is comprised of only two pairs of spiracles (=oligopneustic), the claws are pectinate, and the abdominal sternite VIII is prolonged overlapping the abdominal sternite IX. A parsimony analysis based on 18 informative larval characteristics was conducted with the program PAUP*. The most parsimonious trees confirm Meruidae as a relatively basal lineage within the Dytiscoidea. Both Meru Spangler & Steiner and Noteridae are hypothesized to have diverged anterior to Amphizoidae, Aspidytidae, Hygrobiidae, and Dytiscidae

    A Systematic Analysis of Fe II Emission in Quasars: Evidence for Inflow to the Central Black Hole

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    Broad Fe II emission is a prominent feature of the optical and ultraviolet spectra of quasars. We report on a systematical investigation of optical Fe II emission in a large sample of 4037 z < 0.8 quasars selected from the Sloan Digital Sky Survey. We have developed and tested a detailed line-fitting technique, taking into account the complex continuum and narrow and broad emission-line spectrum. Our primary goal is to quantify the velocity broadening and velocity shift of the Fe II spectrum in order to constrain the location of the Fe II-emitting region and its relation to the broad-line region. We find that the majority of quasars show Fe II emission that is redshifted, typically by ~ 400 km/s but up to 2000 km/s, with respect to the systemic velocity of the narrow-line region or of the conventional broad-line region as traced by the Hbeta line. Moreover, the line width of Fe II is significantly narrower than that of the broad component of Hbeta. We show that the magnitude of the Fe II redshift correlates inversely with the Eddington ratio, and that there is a tendency for sources with redshifted Fe II emission to show red asymmetry in the Hbeta line. These characteristics strongly suggest that Fe II originates from a location different from, and most likely exterior to, the region that produces most of Hbeta. The Fe II-emitting zone traces a portion of the broad-line region of intermediate velocities whose dynamics may be dominated by infall.Comment: 20 pages, 14 figures, accepted for publication in Ap

    Deciphering species-specific pollen tube guidance in Solanum

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    Small, secreted cysteine-rich proteins (CRPs)combine a highly stable cysteine spacing,ensuring conservation of their 3D structure andfunction, and hypervariable inter-cysteine blocks, allowing quick evolution of specific recognition domains. Interestingly, several CRPs were shown to control key pollen-pistil interactions in aspecies-specific way. The most emblematicexample is perhaps the LURE defensin-likefamily, controlling directional guidance of pollentubes (PTs) in Torenia and Arabidopsis.We chose wild potatoes (Solanum sect. Petota) asa case study to investigate the impact of rapidCRP divergence in plant speciation. Gathering ~200 close species with overlapping distribution areas, this taxon indeed exhibits strong reproductive isolation. Lab-on-a-chipmicrofluidic experiments carried out on 4 species show that species-preferential PT attraction is a key factor in this isolation. We suspect polymorphic CRPs to control this attraction. High-throughput sequencing technologies were applied to profile the ovule secretome as well as the reproductive transcriptomes of our 4 speciesof interest. To screen out candidate genes, we developped KAPPA, a sequence search algorithm specifically dedicated to CRPs, and obtained a set of 32 defensin-like groups expressed in ovules. Five promising chemoattractant candidates exhibiting (i) ovule-specific expression, (ii) down-regulation in guidance-defective ovules, and (iii) interspecific divergence were selectedfor further characterization. They are currently being investigated with on-gel assays and specific microfluidic devices tailored for Solanum PTs. This study will lead to a better understanding of CRP-mediated PT chemoattraction as one of the major species-specificity checkpoints that mustbe unlocked by pollen tubes in the pistil.Fil: Joly, V.. Institut de Recherche En Biologie Végétale; CanadáFil: Viallet, C.. Institut de Recherche En Biologie Végétale; CanadáFil: Liu, Y.. Institut de Recherche En Biologie Végétale; CanadáFil: Zaro, A.. Universidad de Barcelona; EspañaFil: Ceriotti, Luis Federico. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Matton, D. P.. Institut de Recherche En Biologie Végétale; CanadáEastern Regional MeetingMontrealCanadáCanadian Society of Plant BiologistsMcGill Universit

    El género Dyscinetus Harold (Coleoptera: Scarabaeidae: Dynastinae: Cyclocephalini) en Venezuela y la descripción de una nueva especie

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    El género Dyscinetus Harold, 1869 (Coleoptera: Scarabaeidae: Dynastinae: Cyclocephalini) es redescrito y comparado con Chalepides Casey, 1915 (Cyclocephalini). De las seis especies encontradas en Venezuela quatro son redescritas, una es transferida de Chalepides y redescrita y una es nueva: Dyscinetus dytiscoides Arrow, 1911, D. paradytis (Ponchel & Dechambre, 2003) comb. nov., D. dubius (Olivier, 1789), D. rugifrons (Burmeister, 1847) nuevo registro para el país, D. olivaceus Höhne, 1923 y D. mendax sp. nov., esta última de amplia distribución en América del Sur (Bolivia, Brasil, Ecuador, Guayana Francesa, Perú, Trinidad y Surinam) y usualmente confundida con D. olivaceus. Se presentan clave para identificar las especies venezolanas, ilustraciones de los caracteres de diagnóstico, algunos hospedadores y mapas de distribución.The genus Dyscinetus Harold, 1869 (Coleoptera: Scarabaeidae: Dynastinae: Cyclocephalini) is redescribed and compared with Chalepides Casey, 1915 (Cyclocephalini). Six species occur in Venezuela, four are redescribed, one is transferred from Chalepides and redescribed, and one is a new species: Dyscinetus dytiscoides Arrow, 1911, D. paradytis (Ponchel & Dechambre, 2003) comb. nov., D. dubius (Olivier, 1789), D. rugifrons (Burmeister, 1847), new country record, D. olivaceus Höhne, 1923 and D. mendax sp. nov., the last one is usually confused with D. olivaceus and is widely distributed in South America (Bolivia, Brazil, Ecuador, French Guiana, Peru, Trinidad and Suriname). Identification key for Venezuelan species, diagnostic illustrations, some host data and maps are included

    Dos especies nuevas del género Bubiscus (Coleoptera, Chrysomelidae, Alticinae) de Ecuador

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    El género Busbiscus fue descrito por Savini et al. 2009 en base a la especie B. voseri de Costa Rica. Se describen dos especies nuevas, Bubiscus carinatus y Bubiscus napo provenientes de Ecuador y se incluye una clave de identificación para las tres especies descritas del género.The genus Busbiscus Savini et al. 2009 was described based on the species B. voseri from Costa Rica. Two new species, Bubiscus carinatus and Bubiscus napo from Ecuador are described. A key to the three species is presented

    Long time behaviour of the solution of Maxwell's equations in dissipative generalized Lorentz materials (I) A frequency dependent Lyapunov function approach

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    It is well-known that electromagnetic dispersive structures such as metamaterials can be modelled by generalized Drude-Lorentz models. The present paper is the first of two articles dedicated to dissipative generalized Drude-Lorentz open structures. We wish to quantify the loss in such media in terms of the long time decay rate of the electromagnetic energy for the corresponding Cauchy problem. By using an approach based on frequency dependent Lyapounov estimates, we show that this decay is polynomial in time. These results extend to an unbounded structure the ones obtained for bounded media in [18] via a quite different method based on the notion of cumulated past history and semi-group theory. A great advantage of the approach developed here is to be less abstract and directly connected to the physics of the system via energy balances

    Long time behaviour for electromagnetic waves in dissipative Lorentz media

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    International audienceA very general class of models for describing the propagation of waves in dispersive electromagnetic media is provided by generalized Lorentz models. In this work, we study the long time behaviour of the solutions of the dissipative version of these models
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