187 research outputs found

    Isolation of high quality graphene from Ru by solution phase intercalation

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    2013 AIP Publishing LL

    Molecular and biological characterization of an isolate of Tomato mottle mosaic virus (ToMMV) infecting tomato and other experimental hosts in eastern Spain

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    [EN] Tomato is known to be a natural and experimental reservoir host for many plant viruses. In the last few years a new tobamovirus species, Tomato mottle mosaic virus (ToMMV), has been described infecting tomato and pepper plants in several countries worldwide. Upon observation of symptoms in tomato plants growing in a greenhouse in Valencia, Spain, we aimed to ascertain the etiology of the disease. Using standard molecular techniques, we first detected a positive sense single-stranded RNA virus as the probable causal agent. Next, we amplified and sequenced its full-length genomic RNA which identified the virus as a new ToMMV isolate. Through extensive assays on distinct plant species, we investigated the host range of the Spanish ToMMV isolate. Several plant species were locally and/or systemically infected by the virus, some of which had not been previously reported as ToMMV hosts despite they are commonly used in research greenhouses. Finally, two reliable molecular diagnostic techniques were developed and used to assess the presence of ToMMV. This is the first observation of ToMMV in tomato plants in Europe. We discuss the possibility that, given the high sequence homology between ToMMV and Tomato mosaic virus, the former may have been mistakenly diagnosed as the latter by serological methods.This work was supported by grants BFU2015-70261-P and BFU2015-65037-P (to C.H. and S.F.E., respectively) from Spain Ministry of Economy, Industry and Competitiveness/FEDER.Ambros Palaguerri, S.; Martinez, F.; Ivars, P.; Hernandez Fort, C.; De La Iglesia Jordán, F.; Elena Fito, SF. (2017). Molecular and biological characterization of an isolate of Tomato mottle mosaic virus (ToMMV) infecting tomato and other experimental hosts in eastern Spain. European Journal of Plant Pathology. 149(2):261-268. https://doi.org/10.1007/s10658-017-1180-2S2612681492Fillmer, K., Adkins, S., Pongam, P., & D’Ella, T. (2015). Complete genome sequence of a Tomato mottle mosaic virus isolated from the United States. Genome Announcements, 3(2), e00167–e00115.Hadas, R., Pearlsman, M., Gefen, T., Lachman, O., Hadar, E., Sharabany, G., et al. (2004). Indexing system for Tomato mosaic virus (ToMV) in commercial tomato seed lots. Phytoparasitica, 32(4), 421–424.Lewandowski, D. J., & Dawson, W. O. (1998). Tobamoviruses. In A. Granoff & R. G. Webster (Eds.), Encyclopedia of virology (Vol. 3, 2nd ed., pp. 1780–1783). New York: Academic Press Inc..Li, R., Gao, S., Fel, Z., & Ling, K. (2013). Complete genome sequence of a new Tobamovirus naturally infecting tomatoes in Mexico. Genome Announcements, 1(5), e00794–e00713.Li, Y. Y., Wang, C. L., Xiang, D., Li, R. H., Liu, Y., & Li, F. (2014). First report of Tomato mottle mosaic virus infection of pepper in China. Plant Disease, 98(10), 1447.Martin, D. P., Murrell, B., Golden, M., Khoosal, A., Muhire, B. (2015). RDP4: detection and analysis of recombination patterns in virus genomes. Virus Evolution, 1(1), vev003.Moreira, S. R., Eiras, M., Chaves, A. L. R., Galleti, S. R., & Colariccio, A. (2003). Characterição de uma nova estirpe do Tomato mosaic virus isolada de tomateiro no estado de São Paulo. Fitopatologia Brasileira, 28(6), 602–607.Padmanabhan, C., Zheng, Y., Li, R., Martin, G. B., Fei, Z., & Ling, K. S. (2015). Complete genome sequence of a tomato-infecting Tomato mottle mosaic virus in New York. Genome Announcements, 3(6), e01523–e01515.Pirovano, W., Boetzer, M., Miozzi, L., & Pantaleo, V. (2015). Bioinformatics approaches for viral metagenomics in plants using short RNAs: Model case of study and application to a Cicer arietinum population. Frontiers in Microbiology, 5, 790.Ruiz-Ruiz, S., Moreno, P., Guerri, J., & Ambrós, S. (2006). The complete nucleotide sequence of a severe stem pitting isolate of Citrus tristeza virus from Spain: Comparison with isolates from different origins. Archives of Virology, 151(2), 387398.Salem, N., Mansour, A., Ciuffo, M., Falk, B. W., & Turina, M. (2016). A new tobamovirus infecting tomato crops in Jordan. Archives of Virology, 161(2), 503–506.Soler, S., Prohens, J., López, C., Aramburu, J., Galipienso, L., & Nuez, F. (2010). Viruses infecting tomato in València, Spain: Occurrence, distribution and effect of seed origin. Journal of Phytopathology, 158(11–12), 797–805.Tamura, L., Stecher, G., Peterson, D., Filipski, A., & Kumar, S. (2013). MEGA6: Molecular evolutionary genetics analysis version 6.0. Molecular Biology and Evolution, 30(12), 2725–2729.Turina, M., Geraats, B. P. J., & Ciuffo, M. (2016). First report of Tomato mottle mosaic virus in tomato crops in Israel. New Disease Reports, 33, 1.Webster, C. G., Rosskopf, E. N., Lucas, L., Mellinger, H. C., & Adkins, S. (2014). First report of Tomato mottle mosaic virus infecting tomato in the United States. Plant Health Progress. doi: 10.1094/PHP-BR-14-0023

    Universal sex differences in the desire for sexual variety: tests from 52 nations, 6 Continents, and 13 Islands

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    Evolutionary psychologists have hypothesized that men and women possess both long-term and short-term mating strategies, with men's short-term strategy differentially rooted in the desire for sexual variety. In this article, findings from a cross-cultural survey of 16,288 people across 10 major world regions (including North America, South America, Western Europe, Eastern Europe, Southern Europe, Middle East, Africa, Oceania, South/Southeast Asia, and East Asia) demonstrate that sex differences in the desire for sexual variety are culturally universal throughout these world regions. Sex differences were evident regardless of whether mean, median, distributional, or categorical indexes of sexual differentiation were evaluated. Sex differences were evident regardless of the measures used to evaluate them. Among contemporary theories of human mating, pluralistic approaches that hypothesize sex differences in the evolved design of short-term mating provide the most compelling account of these robust empirical findings

    Performance of a quasi-steady, multi megawatt, coaxial plasma thruster

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    The Los Alamos National Laboratory Coaxial Thruster Experiment (CTX) has been upgraded to enable the quasisteady operation of magnetoplasmadynamic (MPD) type thrusters at power levels from 2 to 40 MW for 10 ms. Diagnostics include an eight position, three axis magnetic field probe to measure magnetic field fluctuations during the pulse; a triple Langmuir probe to measure ion density, electron temperature, and plasma potential; and a time-of-flight neutral particle spectrometer to measure specific impulse. Here we report on the experimental observations and associated analysis and interpretation of long-pulse, quasisteady, coaxial thruster performance in the CTX device

    Preparation, characterization and catalytic behavior for propanepartial oxidation of Ga-promoted MoVTeO catalysts

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    [EN] Two sets of Ga-promoted MoVTeO catalysts were synthesized hydrothermally and heat-treated at 600 degrees C in N-2: (i) materials prepared from gels with Mo/V/Te/Ga atomic ratios of 1/0.60/0.17/x (x=0-0.12) (A-series) and (ii) materials prepared from gels with Mo/V/Te/Ga atomic ratios of 1/0.60-x/0.17/x (x=0.15 or 0.25) (B-series). In addition, a Ga-containing MoVTeO catalyst was also prepared from M1-containing MoVTeO material by impregnation with aqueous solution of gallium and heat-treated at 450 degrees C in N-2. Catalysts were characterized by means of powder XRD, TEM, Raman spectroscopy, NH3-TPD and XPS and tested in the partial oxidation of propane. The results showed that the addition of small amount of gallium significantly increase the selectivity to acrylic acid (AA) at low propane conversion. However, at high propane conversion, the selectivity to AA strongly depends on both the catalyst composition and the gallium incorporation method. The higher selectivity to acrylic acid over Ga-containing MoVTeO catalysts has been related to: (i) structural changes in the M1 phase by the incorporation of Ga3+ into the octahedral structural framework and/or (ii) incorporation of Ga3+ species on the catalyst surface thus modifying catalysts acid properties. (C) 2014 Elsevier B.V. All rights reserved.Financial support from DGICYT in Spain (Project CTQ2012-37925-C03-1 and Program Severo Ochoa SEV-2012-0267) is gratefully acknowledged. EGG acknowledges finantial support through spanish project MAT2010-19837-C06-05 and the ICTS-Microscopia Electronica in Madrid for facilities.Hernández Morejudo, S.; Massó Ramírez, A.; García-González, E.; Concepción Heydorn, P.; López Nieto, JM. (2015). Preparation, characterization and catalytic behavior for propanepartial oxidation of Ga-promoted MoVTeO catalysts. Applied Catalysis A: General. 504:51-61. https://doi.org/10.1016/j.apcata.2014.12.039S516150

    Chemical, Structural, and Morphological Changes of a MoVTeNb Catalyst during Oxidative Dehydrogenation of Ethane

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    MoVTeNb mixed oxide, a highly active and selective catalyst for the oxidative dehydrogenation of ethane to produce ethylene, exhibits the so-called M1 and M2 crystalline phases. The thermal stability of the MoVTeNb catalytic system was assessed under varying reaction conditions; to this end, the catalyst was exposed to several reaction temperatures spanning from 440 to 550 °C. Both the pristine and spent materials were analyzed by several characterization techniques. The catalyst was stable below 500 °C; a reaction temperature of ≥500 °C brings about the removal of tellurium from the intercalated framework channels of the M1 crystalline phase. Rietveld refinement of X-ray diffraction patterns and microscopy results showed that the tellurium loss causes the progressive partial destruction of the M1 phase, thus decreasing the number of active sites and forming a MoO2 crystalline phase, which is inactive for this reaction. Raman spectroscopy confirmed the MoO2 phase development as a function of reaction temperature. From highresolution transmission electron microscopy and energy-dispersive X-ray spectroscopy analyses it was noticed that tellurium departure occurs preferentially from the end sides of the needlelike M1 crystals, across the [001] plane. Detailed analysis of a solid deposited at the reactor outlet showrf that it consisted mainly of metallic tellurium, suggesting that the tellurium detachment occurs via reduction of Te4+ to Te0 due to a combination of reaction temperature and feed composition. Thus, in order to sustain the catalytic performance exhibited by MoVTeNb mixed oxide, hot spots along the reactor bed should be avoided or controlled, maintaining the catalytic bed temperature below 500 °C.This work was financially supported by the Instituto Mexicano del Petroleo.Valente, JS.; Armendariz-Herrera, H.; Quintana-Solorzano, R.; Del Angel, P.; Nava, N.; Masso Ramírez, A.; López Nieto, JM. (2014). Chemical, Structural, and Morphological Changes of a MoVTeNb Catalyst during Oxidative Dehydrogenation of Ethane. ACS Catalysis. 4:1292-1301. doi:10.1021/cs500143jS12921301

    Assessing the complex sponge microbiota: core, variable and species-specific bacterial communities in marine sponges

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    Marine sponges are well known for their associations with highly diverse, yet very specific and often highly similar microbiota. The aim of this study was to identify potential bacterial sub-populations in relation to sponge phylogeny and sampling sites and to define the core bacterial community. 16S ribosomal RNA gene amplicon pyrosequencing was applied to 32 sponge species from eight locations around the world's oceans, thereby generating 2567 operational taxonomic units (OTUs at the 97% sequence similarity level) in total and up to 364 different OTUs per sponge species. The taxonomic richness detected in this study comprised 25 bacterial phyla with Proteobacteria, Chloroflexi and Poribacteria being most diverse in sponges. Among these phyla were nine candidate phyla, six of them found for the first time in sponges. Similarity comparison of bacterial communities revealed no correlation with host phylogeny but a tropical sub-population in that tropical sponges have more similar bacterial communities to each other than to subtropical sponges. A minimal core bacterial community consisting of very few OTUs (97%, 95% and 90%) was found. These microbes have a global distribution and are probably acquired via environmental transmission. In contrast, a large species-specific bacterial community was detected, which is represented by OTUs present in only a single sponge species. The species-specific bacterial community is probably mainly vertically transmitted. It is proposed that different sponges contain different bacterial species, however, these bacteria are still closely related to each other explaining the observed similarity of bacterial communities in sponges in this and previous studies. This global analysis represents the most comprehensive study of bacterial symbionts in sponges to date and provides novel insights into the complex structure of these unique associations

    Proliferation of hydrocarbon-degrading microbes at the bottom of the Mariana Trench

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    Background: The Mariana Trench is the deepest known site in the Earth’s oceans, reaching a depth of ~ 11,000m 20 at the Challenger Deep. Recent studies reveal that hadal waters harbor distinctive microbial planktonic communities. However, the genetic potential of microbial communities within the hadal zone is poorly understood. Results: Here, implementing both culture-dependent and culture-independent methods, we perform extensive analysis of microbial populations and their genetic potential at different depths in the Mariana Trench. Unexpectedly, we observed an abrupt increase in the abundance of hydrocarbon-degrading bacteria at depths > 10,400m in the Challenger Deep. Indeed, the proportion of hydrocarbon-degrading bacteria at > 10,400m is the highest observed in any natural environment on Earth. These bacteria were mainly Oleibacter, Thalassolituus, and Alcanivorax genera, all of which include species known to consume aliphatic hydrocarbons. This community shift towards hydrocarbon degraders was accompanied by increased abundance and transcription of genes involved in alkane degradation. Correspondingly, three Alcanivorax species that were isolated from 10,400m water supplemented with hexadecane were able to efficiently degrade n-alkanes under conditions simulating the deep sea, as did a reference Oleibacter strain cultured at atmospheric pressure. Abundant n-alkanes were observed in sinking particles at 2000, 4000, and 6000m (averaged 23.5 μg/gdw) and hadal surface sediments at depths of 10,908, 10,909, and 10,911m (averaged 2.3 μg/gdw). The δ2H values of n-C16/18 alkanes that dominated surface sediments at near 11,000-m depths ranged from − 79 to − 93‰, suggesting these alkanes may derive from an unknown biological source. Conclusions: These results reveal that hydrocarbon-degrading microorganisms are present in great abundance in the deepest seawater on Earth and shed a new light on potential biological processes in this extreme environment

    Heterologous Expression of Alteromonas macleodii and Thiocapsa roseopersicina [NiFe] Hydrogenases in Synechococcus elongatus

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    Oxygen-tolerant [NiFe] hydrogenases may be used in future photobiological hydrogen production systems once the enzymes can be heterologously expressed in host organisms of interest. To achieve heterologous expression of [NiFe] hydrogenases in cyanobacteria, the two hydrogenase structural genes from Alteromonas macleodii Deep ecotype (AltDE), hynS and hynL, along with the surrounding genes in the gene operon of HynSL were cloned in a vector with an IPTG-inducible promoter and introduced into Synechococcus elongatus PCC7942. The hydrogenase protein was expressed at the correct size upon induction with IPTG. The heterologously-expressed HynSL hydrogenase was active when tested by in vitro H2 evolution assay, indicating the correct assembly of the catalytic center in the cyanobacterial host. Using a similar expression system, the hydrogenase structural genes from Thiocapsa roseopersicina (hynSL) and the entire set of known accessory genes were transferred to S. elongatus. A protein of the correct size was expressed but had no activity. However, when the 11 accessory genes from AltDE were co-expressed with hynSL, the T. roseopersicina hydrogenase was found to be active by in vitro assay. This is the first report of active, heterologously-expressed [NiFe] hydrogenases in cyanobacteria
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