1,256 research outputs found

    Complex of primary and secondary parasitoids (Hymenoptera: Encyrtidae and Signiphoridae) of Hypogeococcus spp. Mealybugs (Hemiptera: Pseudococcidae) in the New World

    Get PDF
    Se informan los resultados de los relevamientos de los parasitoides primarios y secundarios (hiperparasitoides) de Hypogeococcus spp. (Hemiptera: Pseudococcidae) realizados en el Nuevo Mundo durante el período 2009 para 2017 para obtener enemigos naturales de la cochinilla harinosa de los cactus (Harrisia cactus mealybug) Hypogeococcus sp., que está devastando cactus nativos en Puerto Rico y amenaza a los cactus presentes en Islas del Caribe adyacentes. Se registraron cinco especies de Encyrtidae (Hymenoptera: Chalcidoidea) como parasitoides primarios de Hypogeococcus spp., incluyendo el recientemente descrito Leptomastidea hypogeococci Triapitsyn sp. n., que es la única especie del género Leptomastidea García Mercet en el Nuevo Mundo cuya clava de la antena de la hembra es contrastantemente blanca. El análisis genético de los individuos de L. hypogeococci de Argentina, Brasil y Puerto Rico (EE. UU.) corrobora los datos morfológicos de que la misma especie se encuentra en América del Sur, las islas del Caribe y Florida (EE. UU.). Se proporciona una clave para las especies del Nuevo Mundo de Leptomastidea. Leptomastidea antillicola Dozier, syn. n. de Puerto Rico es sinonimizado bajo L. abnormis (Girault). Basado en los datos moleculares presentados, Anagyrus ciomperliki Triapitsyn syn. n. (Encyrtidae), originalmente descrito de Puerto Rico, es sinonimizado bajo A. quilmes Triapitsyn, Logarzo & Aguirre, cuyo rango de distribución conocido también se amplía para incluir a Brasil. Anagyrus cachamai Triapitsyn, Logarzo y Aguirre, A. lapachosus Triapitsyn, Aguirre y Logarzo y A. quilmes se registraron recientemente en Paraguay. Se describe el macho previamente desconocido de Prochiloneurus argentinensis (De Santis) (Encyrtidae) de la provincia de Misiones de Argentina, y el de P. narendrani Noyes & Triapitsyn de la Isla de Mona, Puerto Rico. Hasta aquí, Anagyrus cachamai y A. lapachosus se consideran como las principales especies para la introducción desde Argentina y Paraguay a Puerto Rico para el control biológico de la cochinilla harinosa de los cactus. El holotipo de Anagyrus tanystis De Santis de Buenos Aires, Argentina, cuyos hospederos asociados son desconocidos, se ilustra para facilitar su reconocimiento de otras especies congenéricas.Parasitoids, both primary and secondary (hyperparasitoids), of Hypogeococcus spp. mealybugs (Hemiptera: Pseudococcidae) are reviewed to report results of the surveys in the New World conducted during 2009 to 2017 for prospective natural enemies of the Harrisia cactus mealybug, Hypogeococcus sp., which is devastating native cacti in Puerto Rico and threatening cacti in the adjacent Caribbean islands. Five species of Encyrtidae (Hymenoptera: Chalcidoidea) are recorded as primary parasitoids of Hypogeococcus spp., including the newly described Leptomastidea hypogeococci Triapitsyn sp. n., which is the only species of the genus Leptomastidea García Mercet in the New World where the clava of the female antenna is contrastingly white. Genetic analysis of the individuals of L. hypogeococci from Argentina, Brazil, and Puerto Rico (USA) corroborates the morphological data that the same species occurs in South America, the Caribbean islands, and Florida (USA). A key to the New World species of Leptomastidea is given and taxonomic notes are provided on its other known species in the Neotropical region. Leptomastidea antillicola Dozier, syn. n. from Puerto Rico is synonymized under L. abnormis (Girault). Based on the presented molecular data, Anagyrus ciomperliki Triapitsyn syn. n. (Encyrtidae), originally described from Puerto Rico, is synonymized under A. quilmes Triapitsyn, Logarzo & Aguirre, where the known distributional range is expanded to also include Brazil. Anagyrus cachamai Triapitsyn, Logarzo & Aguirre, A. lapachosus Triapitsyn, Aguirre & Logarzo, and A. quilmes are newly recorded from Paraguay. The previously unknown male of Prochiloneurus argentinensis (De Santis) (Encyrtidae) is described from Misiones Province of Argentina, and that of P. narendrani Noyes & Triapitsyn is described from Mona Island, Puerto Rico. So far, Anagyrus cachamai and A. lapachosus are considered to be the primary target species for introduction from Argentina and Paraguay into Puerto Rico for the biological control of Harrisia cactus mealybug. The holotype of Anagyrus tanystis De Santis from Buenos Aires, Argentina, host associations are unknown, and is illustrated to facilitate its recognition from other congeneric species.Fil: Triapitsyn, Serguei V.. University of California; Estados UnidosFil: Aguirre, María Belén. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Logarzo, Guillermo Alejandro. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Hight, Stephen D.. United States Department of Agriculture. Agriculture Research Service; Estados UnidosFil: Ciomperlik, Matthew A.. United States Department of Agriculture. Agriculture Research Service; Estados UnidosFil: Rugman Jones, Paul F.. University of California; Estados UnidosFil: Rodrigues, Jose C. Verle. Universidad de Puerto Rico; Puerto Ric

    Population structure, adaptation and divergence of the meadow spittlebug, Philaenus spumarius (Hemiptera, Aphrophoridae), revealed by genomic and morphological data

    Get PDF
    Understanding patterns of population differentiation and gene flow in insect vectors of plant diseases is crucial for the implementation of management programs of disease. We investigated morphological and genome-wide variation across the distribution range of the spittlebug Philaenus spumarius (Linnaeus, 1758) (Hemiptera, Auchenorrhyncha, Aphrophoridae), presently the most important vector of the plant pathogenic bacterium Xylella fastidiosa Wells et al., 1987 in Europe. We found genome-wide divergence between P. spumarius and a very closely related species, P. tesselatus Melichar, 1899, at RAD sequencing markers. The two species may be identified by the morphology of male genitalia but are not differentiated at mitochondrial COI, making DNA barcoding with this gene ineffective. This highlights the importance of using integrative approaches in taxonomy. We detected admixture between P. tesselatus from Morocco and P. spumarius from the Iberian Peninsula, suggesting gene-flow between them. Within P. spumarius, we found a pattern of isolation-by-distance in European populations, likely acting alongside other factors restricting gene flow. Varying levels of co-occurrence of different lineages, showing heterogeneous levels of admixture, suggest other isolation mechanisms. The transatlantic populations of North America and Azores were genetically closer to the British population analyzed here, suggesting an origin from North-Western Europe, as already detected with mitochondrial DNA. Nevertheless, these may have been produced through different colonization events. We detected SNPs with signatures of positive selection associated with environmental variables, especially related to extremes and range variation in temperature and precipitation. The population genomics approach provided new insights into the patterns of divergence, gene flow and adaptation in these spittlebugs and led to several hypotheses that require further local investigation.Peer reviewe

    Infliximab partially impairs the anti-Mycobacterium tuberculosis immune responses of severe psoriasis patients with positive tuberculin skin-test

    Get PDF
    Background Infliximab and etarnecept are now widely used for treating severe psoriasis. However, these drugs, especially infliximab, increased the risk of tuberculosis reactivation. Surprisingly, epidemiological data suggest that the tuberculosis rate in patients taking infliximab in Sao Paulo State, Brazil, is similar to that of some developed, non-endemic countries. Objective The aim of this study was to better understand the effect of infliximab on Mycobacterium tuberculosis (Mtb) immune responses of psoriasis patients in an endemic setting (Brazil). Methods We evaluated the tuberculosis-specific immune responses of severe psoriasis patients and healthy individuals, both tuberculin skin test (TST) positive, in the presence/absence of infliximab. Patients had untreated severe psoriasis, no co-morbidities affecting the immune responses and a TST >10 mm. Healthy TST+ (>10 mm) individuals were evaluated in parallel. PBMC cultures from both groups were stimulated with different Mycobacterium tuberculosis (Mtb) antigens (ESAT-6, 85B and Mtb lysate) and phytohemagglutinin, with or without infliximab (5 mu g/mL). Parameters evaluated were TNF-alpha, IFN-gamma and IL-10 secretion by ELISA, overnight IFN-gamma ELISpot and lymphocyte proliferative response (LPR). Results Infliximab almost abolished TNF-alpha detection in PBMC supernatants of both groups. It also significantly reduced the LPR to phytohemagglutinin and the Mtb antigens as well as the IFN-gamma levels secreted into day 5 supernatants in both groups. There was no concomitant exaggerated IL-10 secretion that could account for the decreases in these responses. ELISpot showed that, contrasting with the central-memory responses above, infliximab did not affect effector-memory INF-gamma-releasing T-cell numbers. Conclusions Infliximab affected some, but not all aspects of the in vitro antituberculosis immune responses tested. The preserved effector-memory responses, putatively related to exposure to environmental mycobacteria, may help to explain the lower than expected susceptibility to tuberculosis reactivation in our setting. Received: 29 December 2010; Accepted: 9 March 2011Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [05/57761-7, 05/60075-8]Netherlands Leprosy Relief Foundation (NLR)European Commissio

    Alpha cluster structure in 16O.

    Get PDF
    The alpha cluster phenomenon in the light nuclei structure has been the subject of a longtime\ud investigation since the proposal of the Ikeda diagrams, however the mechanism of the cluster\ud formation is still not completely understood. In fact, if the clusters have a fairly rigid crystal-like or a\ud gas-like structure remains an open question. The interpretation of the Hoyle state as an α\ud condensate brought a renewed interest to this subject, in particular to resonances analogous to the\ud Hoyle state. In this context the study of the experimental evolution of the α-cluster phenomenon\ud through (6Li,d) transfer reactions has been performed in São Paulo. Particularly important are the\ud regions around the nα thresholds where the α-cluster structure states are predicted. The resonant\ud states around the 4α threshold in the nucleus 16O are the focus of the present contribution. The\ud 12C(6Li,d)16O reaction was measured at a bombarding energy of 25.5 MeV employing the São Paulo\ud Pelletron-Enge-Spectrograph facility and the nuclear emulsion detection technique. Resonant states\ud above the α threshold were measured and an energy resolution of 15-30 keV allows to define states\ud previously unresolved. The angular distributions of the absolute cross sections were determined in a\ud range of 4-40 degree in the center of mass system and up to 17 MeV excitation energy. The upper\ud limit for the resonance widths in the crucial region of the 4α threshold was obtained. These values\ud revealed to be at least a factor three smaller than the ones previously reported in the literature,\ud indicating that the α cluster structure information on this region should be revised

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

    Full text link
    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

    Full text link
    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

    Full text link
    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    High levels of T lymphocyte activation in Leishmania-HIV-1 co-infected individuals despite low HIV viral load

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Concomitant infections may influence HIV progression by causing chronic activation leading to decline in T-cell function. In the Americas, visceral (AVL) and tegumentary leishmaniasis (ATL) have emerged as important opportunistic infections in HIV-AIDS patients and both of those diseases have been implicated as potentially important co-factors in disease progression. We investigated whether leishmaniasis increases lymphocyte activation in HIV-1 co-infected patients. This might contribute to impaired cellular immune function.</p> <p>Methods</p> <p>To address this issue we analyzed CD4<sup>+ </sup>T absolute counts and the proportion of CD8<sup>+ </sup>T cells expressing CD38 in <it>Leishmania</it>/HIV co-infected patients that recovered after anti-leishmanial therapy.</p> <p>Results</p> <p>We found that, despite clinical remission of leishmaniasis, AVL co-infected patients presented a more severe immunossupression as suggested by CD4<sup>+ </sup>T cell counts under 200 cells/mm<sup>3</sup>, differing from ATL/HIV-AIDS cases that tends to show higher lymphocytes levels (over 350 cells/mm<sup>3</sup>). Furthermore, five out of nine, AVL/HIV-AIDS presented low CD4<sup>+ </sup>T cell counts in spite of low or undetectable viral load. Expression of CD38 on CD8<sup>+ </sup>T lymphocytes was significantly higher in AVL or ATL/HIV-AIDS cases compared to HIV/AIDS patients without leishmaniasis or healthy subjects.</p> <p>Conclusions</p> <p><it>Leishmania </it>infection can increase the degree of immune system activation in individuals concomitantly infected with HIV. In addition, AVL/HIV-AIDS patients can present low CD4<sup>+ </sup>T cell counts and higher proportion of activated T lymphocytes even when HIV viral load is suppressed under HAART. This fact can cause a misinterpretation of these laboratorial markers in co-infected patients.</p

    Central Role of Pyrophosphate in Acellular Cementum Formation

    Get PDF
    Background: Inorganic pyrophosphate (PPi) is a physiologic inhibitor of hydroxyapatite mineral precipitation involved in regulating mineralized tissue development and pathologic calcification. Local levels of PPi are controlled by antagonistic functions of factors that decrease PPi and promote mineralization (tissue-nonspecific alkaline phosphatase, Alpl/TNAP), and those that increase local PPi and restrict mineralization (progressive ankylosis protein, ANK; ectonucleotide pyrophosphatase phosphodiesterase-1, NPP1). The cementum enveloping the tooth root is essential for tooth function by providing attachment to the surrounding bone via the nonmineralized periodontal ligament. At present, the developmental regulation of cementum remains poorly understood, hampering efforts for regeneration. To elucidate the role of PPi in cementum formation, we analyzed root development in knock-out ((-/-)) mice featuring PPi dysregulation. Results: Excess PPi in the Alpl(-/-) mouse inhibited cementum formation, causing root detachment consistent with premature tooth loss in the human condition hypophosphatasia, though cementoblast phenotype was unperturbed. Deficient PPi in both Ank and Enpp1(-/-) mice significantly increased cementum apposition and overall thickness more than 12-fold vs. controls, while dentin and cellular cementum were unaltered. Though PPi regulators are widely expressed, cementoblasts selectively expressed greater ANK and NPP1 along the root surface, and dramatically increased ANK or NPP1 in models of reduced PPi output, in compensatory fashion. In vitro mechanistic studies confirmed that under low PPi mineralizing conditions, cementoblasts increased Ank (5-fold) and Enpp1 (20-fold), while increasing PPi inhibited mineralization and associated increases in Ank and Enpp1 mRNA. Conclusions: Results from these studies demonstrate a novel developmental regulation of acellular cementum, wherein cementoblasts tune cementogenesis by modulating local levels of PPi, directing and regulating mineral apposition. These findings underscore developmental differences in acellular versus cellular cementum, and suggest new approaches for cementum regeneration
    corecore