4,206 research outputs found

    Resonant Lepton-Gluon Collisions at the Large Hadron Collider

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    We study the lepton-induced resonant production of color-adjoint leptons (leptogluons) at the LHC employing the lepton parton density function of the proton. We demonstrate that this production mechanism can be useful to extend the LHC ability to search for leptogluons beyond purely quark/gluon initiated production processes up to ~ 3.5 TeV leptogluon masses and O(1) TeV compositeness scales. Discerning leptogluons from scalar and vector leptoquarks is also possible in this channel, given a data sample containing the order of 100 signal events. We argue that the resonant channel can be combined with leptogluon pair and associated leptogluon-lepton productions to boost exclusion limits and discovery prospects at the LHC.Comment: 15 pages, 8 figure

    Same-Sign Taus Signatures of Maximally Flavor-Violating Scalars at the LHC

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    We explore single and double flavor-violating scalars (flavons) production at the 13 and 14 TeV LHC in an effective field theory formulation where flavons always change the flavor of Standard Model fermions. When those scalars couple to mass, their flavor-changing couplings to top quarks and tau leptons are favored. Focusing on the mass region below the top quark mass, we find couplings that fit the muon and electron (g2)(g-2) discrepancies and avoid several current experimental constraints. We determine the potential of the LHC to exclude or discover such a new physics scenario with clean signatures consisting of same-sign tau leptons and the simultaneous observation of resonances in the tau plus electron or muon invariant mass. We found that in the double production mode, effective couplings down to order 10210^{-2} TeV1^{-1} can be probed for flavon masses in the 10-170 GeV range at the HL-LHC at 14 TeV, but couplings down to 0.1 TeV1^{-1} can be excluded at 95\% confidence level with data collected by the 13 TeV LHC in the same mass interval.Comment: 32 pages, 12 figures, 2 table

    Heterologous expression of nifA or nodD genes improves chickpea-Mesorhizobium symbiotic performance

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    Aims The aim of this study was to investigate whether the overexpression of NifA and NodD regulators contribute to the symbiotic improvement of chickpea mesorhizobia. Methods The native strains V-15b, ST-2, and PMI-6 were transformed with extra copies of nifA or nodD genes and several plants trial were performed. Results Plant growth assays showed that nifA overexpression was able to improve the symbiotic effectiveness of V-15b, while nodD overexpression lead to the improvement of ST-2 and PMI-6. Hydroponic assays showed that plants inoculated with V15bnifA+ and PMI6nodD+ started developing nodules earlier than those inoculated with the corresponding control strains. In addition, the number of nodules was always higher in plants inoculated with the strains overexpressing the symbiotic genes. Analysis of histological sections of nodules formed by V15bnifA+ showed a more developed fixation zone when compared with control. On the other hand, nodules induced by PMI6nodD+ did not show a senescent zone, which was observed in nodules from plants inoculated with the control strain. Plants inoculated with PMI6nodD+ and ST2nodD+ showed a higher number of infection threads than the corresponding control inoculations. Conclusion These results indicate that overexpressing nifA and nodD may be an important tool to achieve the improvement of the symbiotic performance of mesorhizobia.The authors thank Dr Alvaro Peix (IRNASA-CSIC) for providing pMP4661 plasmid. Moreover, the authors thank G. Mariano for technical assistance. This work was financed by FEDER Funds through the Operational Program for Competitiveness Factors - COMPETE and National Funds through FCT (Fundação para a Ciência e a Tecnologia), under the Strategic Project UID/AGR/00115/2013, Project nº FCOMP-01-0124-FEDER-028316 (PTDC/BIA-EVF/4158/2012), project POCI-01-0145-FEDER-016810 (PTDC/AGR-PRO/2978/2014) and InAlentejo ALENT-07-0262-FEDER-001871. J. Rodrigo da-Silva acknowledges a PhD fellowship (1254-13-8) from CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior)

    Genetic diversity of the sunflower caterpillar (Chlosyne lacinia saundersii Doubleday and Hewitson) ( Lepidoptera: Nymphalidae) populations determined by molecular RAPD markers.

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    Chlosyne lacinia saundersii is one of the most important pests of sunflower and it is the main target of insecticides applications. Larvae were collected in Londrina (PR), Santa Maria (RS), Dourados (MS), Ribeirão Preto (SP), Brasília (DF), Barreiras (BA), Uberaba (MG) and Vilhena (RO). Genomic DNA was extracted and amplified with ten-mer primers, which produced 101 loci. The size of the RAPD amplicons ranged from 180 to 2564 bp. Polymorphism among populations ranged from 31% to 67%, with the highest polymorphisms of 57% and 67% being detected in Uberaba and Vilhena populations, respectively. Populations with the highest similarity determined with Dice coefficient were from Ribeirão Preto and Barreiras, while insects from Londrina showed the highest similarity among them. Gene flow of C. lacinia saundersii 1.1 was lower than those previously observed for the noctuid Anticarsia gemmatalis Hübner, suggesting that C. lacinia saundersii populations are more isolated than the ones of this noctuid. Through the Analysis of Molecular Variance (AMOVA), RAPD variance was 33.64% among geographical populations and 66.36% within populations. These results suggest that populations of C. lacinia saundersii are genetically structured

    Toxicological Study Employing Repeated Doses of Garcinielliptone FC, a Polyisoprenylated-Benzophenone Isolated from Seed of Platonia Insignis Mart

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    The major constituent from the hexane extract of the seeds of P. insignis is GFC (garcinielliptone FC). Doses of 25, 50and 75 mg/kg of GFC were aseptically suspended in 0.05% Tween 80 dissolved in 0.9% saline (vehicle) and orally administered for30, 90 and 120 consecutive days to adult Swiss mice. In this work, the repeated oral administration, in animals of both sexes,demonstrates that this compound is not able to induce mortality and/or behavioral changes in adult mice. In addition, body weightgain, feed intake and disposal of excreta were not altered by the administration of this compound with repeated doses. Furthermore,no differences in weight and macroscopic structure of the brain, liver, kidney, lung, heart and spleen between groups of male andfemale adult mice were observed after treatment. During the periods of treatment, GFC produced no significant changes onhaematological and biochemical parameters in male and female mice treated with all doses used. The aim of this study was toinvestigate the toxicological potential of GFC through behavioral, hematological, biochemical and morphological parameters inanimals in order to ensure the safe use of Platonia insignis in folk medicine.Fil: Silva, Ana P.. Federal University of Piauí; BrasilFil: Filho, José Carlos C. L. S.. North Union of Parana; BrasilFil: da Costa Júnior, Joaquim S.. Federal Institute of Piauí; BrasilFil: Peláez, Walter José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Faillace, Martín Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Falcão Ferraz, Alexandre de B.. Lutheran University of Brazil; BrasilFil: David, Jorge M.. Institute Of Chemistry, Federal University Of Bahia; Brasil. Universidade Federal da Bahia; BrasilFil: Freitas, Rivelilson M.. Federal University of Bahia; Brasi

    Resíduo desidratado de vitivinícolas do Vale do São Francisco associado a diferentes fontes energéticas na alimentação de ovinos: desempenho animal.

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    Objetivou-se com a realização deste trabalho avaliar o ganho de peso e conversão alimentar em ovinos confinados recebendo dietas contendo resíduo de vitivinícolas associado a diferentes fontes energéticas. Foram utilizados 18 ovinos sem padrão racial definido, não castrados, com peso médio de 23 kg e oito meses de idade. O período experimental constou de 63 dias, sendo as dietas compostas de 50% de resíduo de vitivinícolas e 50% de concentrados energéticos: grão de milho moído (Zea mays), raspa de mandioca (Manihot esculenta) enriquecida com 1,8% de uréia e farelo de palma forrageira (Opuntia ficus) enriquecido com 1,1% de uréia. Para determinação do ganho de peso os animais foram pesados no início do experimento e a cada sete dias e, para coversão alimentar foi feita a relação entre o consumo de matéria seca e ganho de peso total num período de 63 dias. Os ganhos de peso médio diários foram de 117, 71 e 132g; a conversão alimentar 9,50, 13,28 e 11,30, respectivamente para as combinações resíduo e grão de milho moído, raspa de mandioca e farelo de palma. As médias diárias de ganho de peso vivo obtido pelos ovinos ao longo do período de engorda revelaram um bom potencial forrageiro do resíduo de vitivinícolas combinado as diferentes fontes energéticas

    Sexual and size dimorphism in two deep-water hermit crabs (Decapoda: Parapaguridae) from the Western Atlantic Ocean

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    Abstract The Parapaguridae comprises hermit crabs that inhabit deep-water environments. In these environments, shell availability can be limited, mostly consisting of small and fragile-shelled gastropods. Thus, different strategies have evolved to mitigate this limited shell supply. Sympagurus dimorphus (Studer, 1883) lives in association with a zoanthid cnidarian that creates a pseudo-shell that grows with the hermit crab. In contrast, Oncopagurus gracilis (Henderson, 1888) inhabits small, calcified gastropod shells. Therefore, we selected these two species as models to test sexual dimorphism and shape patterns of their chelipeds and cephalothoracic shield, due to their different shelter acquisition methods. We photographed the animals and digitized the images to employ comparative geometric morphometric techniques. We tested the differences in shape between the sexes within each species, and also tested sexual size dimorphism based on centroid size. For O. gracilis, we found shape differences for the chelipeds and cephalothoracic shield, however, we only observed sexual size dimorphism for the chelipeds. For S. dimorphus, an inverse pattern was found, in which females presented more robust chelipeds, and sexual size dimorphism was present in which males were larger. These differences can be reasonably explained by their shelter acquisition methods, in which O. gracilis depends on small shells that limit growth, while S. dimorphus grows with its cnidarian pseudo-shell. The robustness found in the shape patterns may also be related to their behaviors, e.g., in addition to competition for shells, they also fight during mating. However, we emphasize that future studies with other populations of these species are needed for comparative purposes

    Estimating the time-dependent performance of nanocatalysts in fuel cells based on a cost-normalization approach

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    CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESResearchers have developed new catalysts for fuel cells (FC), whose performances are compared after applying different normalization procedures. However, there is not a standard procedure. The current produced from CO electrooxidation was compared for Pt4271119801988CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES454516/2014-2SEM INFORMAÇÃOThe authors acknowledge financial assistance from CNPq (grant No. 454516/2014-2), FUNDECT (grant No. 026/2015), CAPES and FINE

    Methane Emissions from Ruminants on Integrated Crop-Livestock Systems

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    Ruminant livestock produce ~80 million tonnes of methane (CH4) annually, accounting for ~33% of global anthropogenic emissions of CH4 (Beauchemin et al. 2008). CH4 is a powerful greenhouse gas, with global warming potential of 25 (Eckard et al. 2010), and represents a significant loss of dietary energy (2 to 12% of gross energy of feeds; Patra 2012) in the ruminant production system. Despite greenhouse gas (GHG) emissions have become an increasingly important topic worldwide, there is still a high variability around the estimated values of these emissions, mainly about emissions attributable to livestock (range from 8 to 51%; Herrero et al. 2011). This variability creates confusion among researchers, policy makers and the public, particularly in tropical/sub-tropical regions due substantial uncertainties. Therefore, using rigorous and internationally accepted protocols, a Brazilian national project was established in order to contribute for the estimates of GHG emissions attributable to livestock in Brazilian ruminant production systems. Moreover, enteric CH4 emissions are a major challenge for research, in order to develop technologies and strategies for sustainable ruminant production systems in the future (Eckard et al. 2010). In recent years, integrated crop-livestock systems (ICLS) have gained interest due to, for example, the abatement of methane from livestock production: directly through a reduction in CH4 per unit of animal products resulting from the increase on feed quality and animal welfare (i.e. improved environmental temperature for ICLS with trees), and indirectly through reduction of area submitted to land use changes (i.e. leading to a loss of soil C stocks). This paper deals with the preliminary results from CH4 emissions by beef heifers grazing in two ICLS (i.e. production system that integrates corn or soybeans crops, during the warm season, and cattle grazing on a cool season pasture, on the same area and in the same cropping year, with or without trees), how these findings contributes to determine the soil C balance and mitigation measures
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