115 research outputs found

    Diatraea saccharalis history of colonization in the Americas: The case for human-mediated dispersal

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    The sugarcane borer moth, Diatraea saccharalis, is one of the most important pests of sugarcane and maize crops in the Western Hemisphere. The pest is widespread throughout South and Central America, the Caribbean region and the southern United States. One of the most intriguing features of D. saccharalis population dynamics is the high rate of range expansion reported in recent years. To shed light on the history of colonization of D. saccharalis, we investigated the genetic structure and diversity in American populations using single nucleotide polymorphism (SNPs) markers throughout the genome and sequences of the mitochondrial gene cytochrome oxidase (COI). Our primary goal was to propose possible dispersal routes from the putative center of origin that can explain the spatial pattern of genetic diversity. Our findings showed a clear correspondence between genetic structure and the geographical distributions of this pest insect on the American continents. The clustering analyses indicated three distinct groups: one composed of Brazilian populations, a second group composed of populations from El Salvador, Mexico, Texas and Louisiana and a third group composed of the Florida population. The predicted time of divergence predates the agriculture expansion period, but the pattern of distribution of haplotype diversity suggests that human-mediated movement was most likely the factor responsible for the widespread distribution in the Americas. The study of the early history of D. saccharalis promotes a better understanding of range expansion, the history of invasion, and demographic patterns of pest populations in the Americas.Fil: Francischini, Fabricio J. B.. Universidade Estadual de Campinas. Instituto de Biología; BrasilFil: Cordeiro, Erick M. G.. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Campos, Jaqueline B. de. Universidade Estadual de Campinas. Instituto de Biología; BrasilFil: Alves Pereira, Alessandro. Universidade Estadual de Campinas; BrasilFil: Gomes Viana, João Paulo. Universidade Estadual de Campinas. Instituto de Biología; BrasilFil: Wu, Xing. University of Illinois; Estados UnidosFil: Wei, Wei. University of Illinois; Estados UnidosFil: Brown, Patrick. University of Illinois; Estados UnidosFil: Joyce, Andrea. University of California; Estados UnidosFil: Murúa, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Fogliata, Sofia Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Clough, Steven J.. University of Illinois; Estados Unidos. United States Department of Agriculture; Estados UnidosFil: Zucchi, María Inmaculada. Universidade Estadual de Campinas; Brasi

    Commiphora leptophloeos Phytochemical and Antimicrobial Characterization

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    Commiphora leptophloeos is a plant specie usually known for its medicinal purposes in local communities in Northeast Brazil. In order to evaluate its therapeutic potential, we aimed to determine the phytochemical and antimicrobial properties of C. leptophloeos extracts. Thin Layer Chromatography (TLC) was able to detect the presence of phenolic compounds, flavonoids and reducing sugars. Three phenolic compounds were identified by HPLC and described as Gallic, Chlorogenic and Protocatechuic acids. On the other hand, H(1)NMR analysis revealed the presence of hinokinin, a bioactive lignan further characterized in the present work. The minimum inhibitory concentration (MIC) values for hinokinin ranged from 0.0485 to 3.125 mg/mL in different S. aureus clinical isolates and showed a bactericidal activity against MRSA isolated from blood (MMC 0.40 mg/mL) and postoperative secretion (MMC = 3.125 mg/mL). C. leptophloeos extracts also showed antimicrobial activity against Mycobacterium species such as M. smegmatis (MIC = 12.5 mg/mL) and M. tuberculosis (MIC = 52 mg/mL). Additionally, we determined the toxicity of C. leptophloeos by in vitro HC50 tests with hemolytic activity detected of 313 \ub1 0.5 \u3bcg/mL. Our results showed that C. leptophloeos possesses inhibitory properties against MRSA as well as several other clinically important microorganisms. Furthermore, the present work is the first report of the presence of hinokinin in Commiphora genus

    Linking rattiness, geography and environmental degradation to spillover Leptospira infections in marginalised urban settings: An eco-epidemiological community-based cohort study in Brazil

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    Background: Zoonotic spillover from animal reservoirs is responsible for a significant global public health burden, but the processes that promote spillover events are poorly understood in complex urban settings. Endemic transmission of Leptospira, the agent of leptospirosis, in marginalised urban communities occurs through human exposure to an environment contaminated by bacteria shed in the urine of the rat reservoir. However, it is unclear to what extent transmission is driven by variation in the distribution of rats or by the dispersal of bacteria in rainwater runoff and overflow from open sewer systems. Methods: We conducted an eco-epidemiological study in a high-risk community in Salvador, Brazil, by prospectively following a cohort of 1401 residents to ascertain serological evidence for leptospiral infections. A concurrent rat ecology study was used to collect information on the fine-scale spatial distribution of 'rattiness', our proxy for rat abundance and exposure of interest. We developed and applied a novel geostatistical framework for joint spatial modelling of multiple indices of disease reservoir abundance and human infection risk. Results: The estimated infection rate was 51.4 (95%CI 40.4, 64.2) infections per 1000 follow-up events. Infection risk increased with age until 30 years of age and was associated with male gender. Rattiness was positively associated with infection risk for residents across the entire study area, but this effect was stronger in higher elevation areas (OR 3.27 95% CI 1.68, 19.07) than in lower elevation areas (OR 1.14 95% CI 1.05, 1.53). Conclusions: These findings suggest that, while frequent flooding events may disperse bacteria in regions of low elevation, environmental risk in higher elevation areas is more localised and directly driven by the distribution of local rat populations. The modelling framework developed may have broad applications in delineating complex animal-environment-human interactions during zoonotic spillover and identifying opportunities for public health intervention

    Chamber investigation of the formation and transformation of secondary organic aerosol in mixtures of biogenic and anthropogenic volatile organic compounds

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    A comprehensive chamber investigation of photochemical secondary organic aerosol (SOA) formation and transformation in mixtures of anthropogenic (o-cresol) and biogenic (alpha-pinene and isoprene) volatile organic compound (VOC) precursors in the presence of NOx and inorganic seed particles was conducted. To enable direct comparison across systems, the initial concentration (hence reactivity) of the systems towards the dominant OH oxidant was adjusted. Comparing experiments conducted in single-precursor systems at various initial reactivity levels (referenced to a nominal base case VOC concentration, e.g. halving the initial concentration for a 1/2 initial reactivity experiment) as well as their binary and ternary mixtures, we show that the molecular interactions from the mixing of the precursors can be investigated and discuss challenges in their interpretation. The observed average SOA particle mass yields (the organic particle mass produced for a mass of VOC consumed) in descending order were found for the following systems: alpha-pinene (32 +/- 7 %), alpha-pinene-o-cresol (28 +/- 9 %), alpha-pinene at 1/2 initial reactivity (21 +/- 5 %), alpha-pinene-isoprene (16 +/- 1 %), alpha-pinene at 1/3 initial reactivity (15 +/- 4 %), o-cresol (13 +/- 3 %), alpha-pinene-o-cresol-isoprene (11 +/- 4 %), o-cresol at 1/2 initial reactivity (11 +/- 3 %), o-cresol-isoprene (6 +/- 2 %), and isoprene (0 +/- 0 %). We find a clear suppression of the SOA mass yield from alpha-pinene when it is mixed with isoprene, whilst no suppression or enhancement of SOA particle yield from o-cresol was found when it was similarly mixed with isoprene. The alpha-pinene-o-cresol system yield appeared to be increased compared to that calculated based on the additivity, whilst in the alpha-pinene-o-cresol-isoprene system the measured and predicted yields were comparable. However, in mixtures in which more than one precursor contributes to the SOA particle mass it is unclear whether changes in the SOA formation potential are attributable to physical or chemical interactions, since the reference basis for the comparison is complex. Online and offline chemical composition as well as SOA particle volatility, water uptake, and "phase" behaviour measurements that were used to interpret the SOA formation and behaviour are introduced and detailed elsewhere.ISSN:1680-7375ISSN:1680-736

    Modular hybrid total hip arthroplasty. Experimental study in dogs

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    Background: This prospective experimental study evaluated the surgical procedure and results of modular hybrid total hip arthroplasty in dogs.Methods: Ten skeletally mature healthy mongrel dogs with weights varying between 19 and 27 kg were used. Cemented modular femoral stems and uncemented porous-coated acetabular cups were employed. Clinical and radiographic evaluations were performed before surgery and at 30, 60, 90, 120, 180 and 360 days post-operation.Results: Excellent weight bearing was noticed in the operated limb in seven dogs. Dislocation followed by loosening of the prosthesis was noticed in two dogs, which were therefore properly treated with a femoral head osteotomy. Femoral fracture occurred in one dog, which was promptly treated with full implant removal and femoral osteosynthesis.Conclusions: The canine modular hybrid total hip arthroplasty provided excellent functionality of the operated limb

    Importation and early local transmission of COVID-19 in Brazil, 2020

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    We conducted the genome sequencing and analysis of the first confirmed COVID-19 infections in Brazil. Rapid sequencing coupled with phylogenetic analyses in the context of travel history corroborate multiple independent importations from Italy and local spread during the initial stage of COVID-19 transmission in Brazil
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