1,278 research outputs found

    EVALUACIÓN DEL EFECTO INSECTICIDA Y REPELENTE DEL POLVO DE Chenopodium ambrosioides SOBRE ADULTOS DE Callosobruchus maculatus F. (COLEOPTERA, BRUCHIDAE) EN SEMILLAS DE POROTO (Vigna unguiculata)

    Get PDF
    Se evaluó el efecto de insecticida y repelente del polvo de Kaarê (Chenopodium ambrosioides), en cuatro concentraciones (1 al 4%), sobre adultos de Callosobruchus maculatus F. en semillas de poroto pyta'í (Vigna unguiculata). El experimento fue realizado en el laboratorio de la División de Entomología de la Facultad de Ciencias Agrarias (FCA) - Universidad Nacional de Asunción (UNA), San Lorenzo; los materiales biológicos fueron mantenidas en una cámara incubadora con 25º ± 2ºC de temperatura y 70% ± 10% de humedad relativa. En este trabajo fueron evaluadas dos variables: mortalidad y repelencia de insectos adultos. Se tuvo un testigo absoluto constituido por las semillas y los insectos adultos, donde se evaluaron las mismas variables y los resultados fueron comparados con los demás tratamientos. Los resultados obtenidos fueron los siguientes: semillas tratadas con 2% y 4% del polvo (Chenopodium ambrosioides), presentaron una mortalidad del 78.85% de insectos adultos a los 5 días, seguidas por las tratadas con 3% y 1%, con 74% y 65%, de mortalidad de insectos adultos respectivamente. El polvo de C. ambrosioides, no repele a C. maculatus en ninguna de las dosis utilizadas

    Whole sequence of the mitochondrial DNA genome of Kearns Sayre Syndrome patients: Identification of deletions and variants

    Get PDF
    Mitochondria both produce the energy of the cell as ATP via respiration and regulate cellular metabolism. Accordingly, any deletion or mutation in the mitochondrial DNA (mtDNA) may result in a disease. One of these diseases is Kearns Sayre syndrome (KSS), described for the first time in 1958, where different large-scale deletions of different sizes and at different positions have been reported in the mitochondrial genome of patients with similar clinical symptoms. In this study, sequences of the mitochondrial genome of three patients with clinic features of KSS were analyzed. Our results revealed the position, heteroplasmy percentage, size of deletions, and their haplogroups. Two patients contained deletions reported previously and one patient showed a new deletion not reported previously. These results display for the first time a systematic analysis of mtDNA variants in the whole mtDNA genome of patients with KSS to help to understand their association with the disease

    Structural study of the type II 3-dehydroquinate dehydratase from Actinobacillus pleuropneumoniae

    Get PDF
    9 pages, 7 figures, 2 tables.The structure of the type II dehydroquinate dehydratase (DHQase) from Actinobacillus pleuropneumoniae, the third enzyme of the shikimate pathway, has been determined. Crystals diffracting to 1.7 Å were obtained in space and on earth using the counter-diffusion technique. The structure was solved using molecular replacement and refined to high resolution. The overall structure of the dodecameric enzyme is described and compared with structures of DHQases from other bacteria. DHQases contain a flexible loop that presumably closes over the active site upon substrate binding. The enzyme can exist in an open or closed conformation. The present structure displays the open conformation, with a sulfate anion bound in the active site. The availability of this structure opens a route to structure-based antibiotics targetting this pathogenic bacterium.We thank Professor Kabsch for providing XDS free of charge. We acknowledge the support of the European Space Agency and the European Community Action to Research Infrastructure Action of the Improving Human Potential Programme to the EMBL Hamburg Outstation, contract No. HPRI-CT-1999-00017. We thank Olivier Minster (ESA) for his support of space science. The authors acknowledge the excellent work of Dr Eva ManÄ as in managing the logistics concerning the space mission. We thank Viscount Dirk Frimout for his support for space crystallization experiments.Peer reviewe

    Compensatory shifts in visual perception are associated with hallucinations in Lewy body disorders

    Get PDF
    Abstract Visual hallucinations are a common, distressing, and disabling symptom of Lewy body and other diseases. Current models suggest that interactions in internal cognitive processes generate hallucinations. However, these neglect external factors. Pareidolic illusions are an experimental analogue of hallucinations. They are easily induced in Lewy body disease, have similar content to spontaneous hallucinations, and respond to cholinesterase inhibitors in the same way. We used a primed pareidolia task with hallucinating participants with Lewy body disorders (n = 16), non-hallucinating participants with Lewy body disorders (n = 19), and healthy controls (n = 20). Participants were presented with visual “noise” that sometimes contained degraded visual objects and were required to indicate what they saw. Some perceptions were cued in advance by a visual prime. Results showed that hallucinating participants were impaired in discerning visual signals from noise, with a relaxed criterion threshold for perception compared to both other groups. After the presentation of a visual prime, the criterion was comparable to the other groups. The results suggest that participants with hallucinations compensate for perceptual deficits by relaxing perceptual criteria, at a cost of seeing things that are not there, and that visual cues regularize perception. This latter finding may provide a mechanism for understanding the interaction between environments and hallucinations

    New morphological and molecular evidence confirm the presence of the Norwegian skate Dipturus nidarosiensis (Storm, 1881) in the Mediterranean Sea and extend its distribution to the western basin

    Get PDF
    The present study confirms the presence of the Norwegian skate Dipturus nidarosiensis (Storm, 1881) in the Mediterranean Sea, by means of morphological traits and molecular markers providing the first record of this species in the Alboran Sea. Cannas et al. (2010) reported D. nidarosiensis for the first time in the Mediterranean from specimens captured in the central western basin, but Ebert & Stehmann (2013) and Stehmann et al. (2015) considered these records "likely refer to the smaller morphotype, Dipturus sp.", a species not yet described. Eight specimens of the Dipturus genus (Rajiformes: Rajidae) were caught off the Alboran Island (western Mediterranean) in 2012, 2013 and 2016, between 620 and 819 m depth. These specimens showed morphometric diagnostic features corresponding to those of Norwegian skates from the Northeast Atlantic and the central western Mediterranean Sea. Moreover, the Alboran individuals were genetically compared to Northeast Atlantic specimens available in GenBank by means of two mitochondrial DNA fragments: cytochrome c oxidase subunit I (COI) and cytochrome b (Cytb). Analyses showed that the Northeast Atlantic Norwegian skate specimens and the Alboran Sea ones were genetically similar and shared haplotypes, corroborating the identification of the Alboran individuals as Dipturus nidarosiensis. However, they were different from other Dipturus species distributed throughout the Northeast Atlantic and the Mediterranean Sea. Our results confirm the occurrence of this deep-sea large skate species in the Mediterranean, although the IUCN Red List of Threatened Species does not consider it possible (Stehmann et al., 2015)Versión del edito

    Luminescence properties of Ce3+ and Tb3+ co-doped SiOxNy thin films: Prospects for color tunability in silicon-based hosts

    Get PDF
    In this work, the role of the nitrogen content, the annealing temperature, and the sample morphology on the luminescence properties of Ce3+ and Tb3+ co-doped SiOxNy thin films has been investigated. An increasing nitrogen atomic percentage has been incorporated in the host matrix by gradually replacing oxygen with nitrogen during fabrication while maintaining the Si content unaltered, obtaining a sequential variation in the film composition from nearly stoichiometric SiO2 to SiOxNy. The study of rare earth doped single layers has allowed us to identify the parameters that yield an optimum optical performance from Ce3+ and Tb3+ ions. Ce3+ ions proved to be highly sensitive to the annealing temperature and the nitrogen content, showing strong PL emission for relatively low nitrogen contents (from 0 to 20%) and moderate annealing temperatures (800-1000 degrees C) or under high temperature annealing (1180 degrees C). Tb3+ ions, on the other hand, displayed a mild dependence on those film parameters. Rare earth co-doping has also been investigated by comparing the luminescence properties of three different approaches: (i) a Ce3+ and Tb3+ co-doped SiOxNy single layer, (ii) a bilayer composed of two SiOxNy single layers doped with either Ce3+ or Tb3+ ions, and (iii) a multilayer composed of a series of either Tb3+ or Ce3+-doped SiOxNy thin films with interleaved SiO2 spacers. Bright green emission and efficient energy transfer from either Ce3+ ions or Ce silicates to Tb3+ ions has been observed in the co-doped single layer as a consequence of the strong ion-ion interaction. On the other hand, independent luminescence from Ce3+ and Tb3+ ions has been observed in the Ce3+ and Tb3+ co-doped bilayer and multilayer, providing a good scenario to develop light emitting devices with wide color tunability by varying the number of deposited films that contain each rare earth dopant. Moreover, the optoelectronic properties of Ce3+-and/or Tb3+-doped thin films have been studied by depositing transparent conductive electrodes over selected samples. An electroluminescence signal according to the rare earth transitions is obtained in all cases, validating the excitation of Ce3+ and Tb3+ ions upon electron injection. Also, the main charge transport of injected electrons has been evaluated and correlated with the layer stoichiometry. Finally, a simple reliability test has allowed disclosing the origin of the early breakdown of test devices, attributed to the excessive joule heating at filament currents that occur around a region close to the polarization point. (C) 2016 AIP Publishing LLC.This research was supported by the Spanish Ministry of Science and Innovation (TEC2012-38540-C02-01). RBS characterization was performed in the Tandetron Accelerator Laboratory at Western University in London, ON (Canada). TEM characterization was carried out in the Science and Technical Centers (CCiT) of the University of Barcelona. In Canada, this work was supported by the Natural Sciences and Engineering Research Council (NSERC) under the Discovery Grants program.Ramirez, JM.; Ruiz-Caridad, A.; Wojcik, J.; Gutiérrez Campo, AM.; Estrade, S.; Peiro, F.; Sanchis Kilders, P.... (2016). Luminescence properties of Ce3+ and Tb3+ co-doped SiOxNy thin films: Prospects for color tunability in silicon-based hosts. Journal of Applied Physics. 119(11):113108-1-113108-14. https://doi.org/10.1063/1.4944433S113108-1113108-141191

    Optimization of the Sequence of Washing Reverse Osmosis Membranes Used for Seawater Desalination

    Get PDF
    Seawater contains a number of organic and inorganic components that cause fouling of membranes when subjected to a process of reverse osmosis desalination. This fouling is one of the most important problems in the management of desalination plants, as it entails a significant loss in system performance. For membranes to be able to continue operating under appropriate conditions, they must undergo periodic cleaning protocols. This paper presents the results obtained when, subjecting a previously fouled aromatic polyamide membrane to different washing agents and using different concentrations of the same. Optimal concentrations of cleaning reagents were established. The results indicate that the performance of cleaning using a mixture of reagents, and alternating alkaline and acidic media, enabled maximum recovery of the membrane permeate flux (94.2 %) and a significant reduction in the consumption of cleaning reagents. This work is licensed under a Creative Commons Attribution 4.0 International License
    corecore