1,015 research outputs found

    The Use of MODIS Images to Quantify the Energy Balance in Different Agroecosystems in Brazil

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    Sugarcane (SC) is expanding over coffee (CO), while both crops have replaced the natural vegetation (NV) in the northeastern side of São Paulo (SP) state, Southeast Brazil. Under these dynamic land-use changes, geosciences are valuable tools for evaluating the large-scale energy and mass exchanges between the vegetation and the lower atmosphere. For quantification of the energy balance components in these mixed agroecosystems, MODIS images were used throughout the Simple Algorithm for Evapotranspiration Retrieving (SAFER) algorithm, during the year 2015 in the main sugarcane- and coffee-growing regions of the state. Regarding, respectively, sugarcane, coffee, and natural vegetation, the fractions of the net radiation (Rn) used as latent heat flux (λE) were 0.68, 0.87, and 0.77, while the corresponding ones for the sensible heat (H) fluxes were 0.27, 0.07, and 0.16. Negative H values were noticed from April to July, because of heat advection raising λE values above Rn, but they were more often in coffee than in sugarcane. It was concluded that sugarcane crop presented lower evapotranspiration rates, when compared with coffee, which could be an advantage under the actual water scarcity scenario. However, sugarcane replacing natural vegetation means environmental warming, while the land use changes promoted by coffee crop represented cooling conditions

    Intracerebral infection with dengue-3 virus induces meningoencephalitis and behavioral changes that precede lethality in mice

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    <p>Abstract</p> <p>Background</p> <p>Dengue, one of the most important arboviral diseases of humans, may cause severe systemic disease. Although dengue virus (DENV) has been considered to be a non-neurotropic virus, dengue infection has been associated recently with a series of neurological syndromes, including encephalitis. In this work, we evaluated behavioral changes and inflammatory parameters in C57BL/6 mice infected with non-adapted dengue virus 3 (DENV-3) genotype I.</p> <p>Methods</p> <p>C57BL/6 mice received 4 × 10<sup>3 </sup>PFU of DENV-3 by an intracranial route. We evaluated the trafficking of leukocytes in brain microvasculature using intravital microscopy, and evaluated chemokine and cytokine profiling by an ELISA test at 3 and 6 days post infection (p.i.). Furthermore, we determined myeloperoxidase activity and immune cell populations, and also performed histopathological analysis and immunostaining for the virus in brain tissue.</p> <p>Results</p> <p>All animals developed signs of encephalitis and died by day 8 p.i. Motor behavior and muscle tone and strength parameters declined at day 7 p.i. We observed increased leukocyte rolling and adhesion in brain microvasculature of infected mice at days 3 and 6 p.i. The infection was followed by significant increases in IFN-γ, TNF-α, CCL2, CCL5, CXCL1, and CXCL2. Histological analysis showed evidence of meningoencephalitis and reactive gliosis. Increased numbers of neutrophils, CD4<sup>+ </sup>and CD8<sup>+ </sup>T cells were detected in brain of infected animals, notably at day 6 p.i. Cells immunoreactive for anti-NS-3 were visualized throughout the brain.</p> <p>Conclusion</p> <p>Intracerebral infection with non-adapted DENV-3 induces encephalitis and behavioral changes that precede lethality in mice.</p

    NIRS and multivariate methods for discrimination of morning glory species at different growth stages

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    Morning glory species are weeds very common in tropical crops, where they cause direct and indirect damage. The management of these species primarily relies on the application of herbicides, disregarding the growth stage and spatial distribution. Studies addressing new techniques for identifying these species may contribute to the development of proximal sensors for carrying out specific and rational management. Thus, the objective of this work was to use near infrared spectroscopy (NIRS) and multivariate analysis to discriminate two species of morning glory in three growth stages. NIRS spectra were collected from Ipomoea hederifolia and Merremia aegyptia were collected at three different stages in the spectral range of 4.000 to 10.000 cm-1. PCA and PC-LDA were used to analyze the entire spectrum and specific bands. NIRS associated with PCA and PC-LDA were sufficient to discriminate I. hederifolia and M. aegyptia species and their growth stages. PCA allowed a proper segregation of stages and species when applied individually PC-LDA correctly classified between 90.93 to 100% of species and stages. The best discrimination results were observed in the NIR spectra ranges from 4.500 to 6.000 cm-1 and 4.500 to 6.000 + 6.500 to 7.750 cm-1. This study represents an advance in the research and implementation of NIRS technology to discriminate weed species for the future development of equipment to assist in the adoption and/or performance of a specific management of weeds, capable of contributing to the reduction in the use of herbicides in crops

    Ancient mitochondrial genomes from the Argentinian Pampas inform the early peopling of the Southern Cone of South America

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    The Southern Cone of South America (SCSA) is a key region for investigations about the peopling of the Americas. However, little is known about the eastern sector, the Argentinian Pampas. We analyzed 18 mitochondrial genomes?7 of which are novel?from human skeletal remains from 3 Early to Late Holocene archaeological sites. The Pampas present a distinctive genetic makeup compared to other Middle to Late Holocene pre-Columbian SCSA populations. We also report the earliest individuals carrying SCSA-specific mitochondrial haplogroups D1j and D1g fromEarly andMiddle Holocene, respectively. Using these deep calibration time points in Bayesian phylogenetic reconstructions, we suggest that the first settlers of the Pampas were part of a single and rapid dispersal 15,600 years ago. Finally, we propose that present-day genetic differences between the Pampas and the rest of the SCSA are due to founder effects, genetic drift, and a partial population replacement 9,000 years ago.Fil: Roca Rada, Xavier. Centre For Ancient Dna, University Of Adelaide; AustraliaFil: Politis, Gustavo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Messineo, Pablo Geronimo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Scheifler, Nahuel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Scabuzzo, Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Entre Ríos. Universidad Nacional de Entre Ríos. Centro de Investigaciones y Transferencia de Entre Ríos; ArgentinaFil: Gonzalez, Mariela Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Harkins, Kelly M.. University of California; Estados UnidosFil: Reich, David. Harvard Medical School; Estados UnidosFil: Souilmi, Yassine. University of Adelaide; AustraliaFil: Teixeira, Joao C. T.. University of Adelaide; AustraliaFil: Llamas, Bastien. University of Adelaide; AustraliaFil: Fehren Schmitz, Lars. University of California; Estados Unido

    Estimation and classification of popping expansion capacity in popcorn breeding programs using NIR spectroscopy

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    One of the most important quality traits in popcorn breeding programs is the popping expansion (PE) capacity of the kernel, which is the ratio of the volume of the popcorn to the weight of the kernel. In this study, we evaluated whether near infrared spectroscopy (NIR spectroscopy) could be used as a tool in popcorn breeding programs to routinely predict and/or discriminate popcorn genotypes on the basis of their PE. Three generations (F1, F2, and F2:3) were developed in three planting seasons by manual cross-pollination and self-pollination. A total of 376 ears from the F2:3 generation were selected, shelled, and subjected to phenotypic analysis. Genetic variability was observed in the F2 and F2:3 generations, and their average PE value was 31.5 ± 6.7 mL.g-1. PE prediction models using partial least square (PLS) regression were developed, and the root mean square error of calibration (RMSEC) was 6.08 mL.g-1, while the coefficient of determination (RC 2) was 0.26. The model developed by principal component analysis with quadratic discriminant analysis (PCA-QDA) was the best for discriminating the kernels with low PE (≤ 30 mL.g-1) from those with high PE (> 30 mL.g-1) with an accuracy of 78%, sensitivity of 81.2%, and specificity of 72.2%. Although NIR spectroscopy appears to be a promising non-destructive method for assessing the PE of intact popcorn kernels for narrow breeding populations, greater variability and larger sample sizes would help improve the robustness of the predictive and classificatory models

    Evoluçao Tardia da Estimulaçao VDD com Cabo-Eletrodo Atrioventricular Unico com Eletrodos Atriais em Passagem

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    Introduçao: A estimulaçao bicameral com cabo-eletrodo único e eletrodos atriais em passagem (modo VDD) está indicada, pela simplicidade, em pacientes com bloqueio atrioventricular (BAV) total e funçao sinusal normal. Entretanto, sua efetividade para sentir a atividade elétrica atrial em longo prazo é questionável. Objetivo: Verificar evoluçao de 92 pacientes com implante de marcapasso VDD em período superior a 5 anos. Métodos: Os sistemas implantados constavam de cabo-eletrodo único com eletrodos atriais em passagem, revestimento fractal SL60 Biotronik e gerador VDD, mantido inicialmente em programaçao padrao. A onda P foi registrada no momento do implante (média de 2,38±1,23 mV) e na última avaliaçao, além de eventos durante a evoluçao (tempo médio de 52,05 meses). Resultado: Observou-se perda do sincronismo atrial em dez (10,87%) pacientes: dois (2,17%) apresentaram fibrilaçao atrial, cinco (5,43%), perda do potencial elétrico atrial e três (3,26%), deslocamento do eletrodo, requerendo reposicionamento. Em dez casos (10,87%), houve necessidade de reprogramaçao para o modo VVI e, em um paciente (1,09%), aperfeiçoamento para o modo DDD. Na última avaliaçao ou na avaliaçao final, 74 (80,43%) pacientes mantinham estimulaçao VDD, sete (7,61%) estavam em outro modo de estimulaçao e 11 (11,96%) haviam falecido. A onda P era de 1,22±0,83 mV, enquanto que, no implante, era de 2,12±0,87 mV; n.s). Conclusao: A estimulaçao VDD com cabo-eletrodo único e eletrodos fractais atriais em passagem permite manter o sincronismo atrioventricular em um percentual elevado de pacientes com atividade elétrica atrial normal. A necessidade de drogas antiarrítmicas ou cronotrópico-negativas deve ser avaliada caso a caso

    Evoluçao Tardia da Estimulaçao VDD com Cabo-Eletrodo Atrioventricular Unico com Eletrodos Atriais em Passagem

    Get PDF
    Introduçao: A estimulaçao bicameral com cabo-eletrodo único e eletrodos atriais em passagem (modo VDD) está indicada, pela simplicidade, em pacientes com bloqueio atrioventricular (BAV) total e funçao sinusal normal. Entretanto, sua efetividade para sentir a atividade elétrica atrial em longo prazo é questionável. Objetivo: Verificar evoluçao de 92 pacientes com implante de marcapasso VDD em período superior a 5 anos. Métodos: Os sistemas implantados constavam de cabo-eletrodo único com eletrodos atriais em passagem, revestimento fractal SL60 Biotronik e gerador VDD, mantido inicialmente em programaçao padrao. A onda P foi registrada no momento do implante (média de 2,38±1,23 mV) e na última avaliaçao, além de eventos durante a evoluçao (tempo médio de 52,05 meses). Resultado: Observou-se perda do sincronismo atrial em dez (10,87%) pacientes: dois (2,17%) apresentaram fibrilaçao atrial, cinco (5,43%), perda do potencial elétrico atrial e três (3,26%), deslocamento do eletrodo, requerendo reposicionamento. Em dez casos (10,87%), houve necessidade de reprogramaçao para o modo VVI e, em um paciente (1,09%), aperfeiçoamento para o modo DDD. Na última avaliaçao ou na avaliaçao final, 74 (80,43%) pacientes mantinham estimulaçao VDD, sete (7,61%) estavam em outro modo de estimulaçao e 11 (11,96%) haviam falecido. A onda P era de 1,22±0,83 mV, enquanto que, no implante, era de 2,12±0,87 mV; n.s). Conclusao: A estimulaçao VDD com cabo-eletrodo único e eletrodos fractais atriais em passagem permite manter o sincronismo atrioventricular em um percentual elevado de pacientes com atividade elétrica atrial normal. A necessidade de drogas antiarrítmicas ou cronotrópico-negativas deve ser avaliada caso a caso

    Human alveolar progenitors generate dual lineage bronchioalveolar organoids

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    Mechanisms of epithelial renewal in the alveolar compartment remain incompletely understood. To this end, we aimed to characterize alveolar progenitors. Single-cell RNA-sequencing (scRNA-seq) analysis of the HTII-280+/EpCAM+ population from adult human lung revealed subclusters enriched for adult stem cell signature (ASCS) genes. We found that alveolar progenitors in organoid culture in vitro show phenotypic lineage plasticity as they can yield alveolar or bronchial cell-type progeny. The direction of the differentiation is dependent on the presence of the GSK-3β inhibitor, CHIR99021. By RNA-seq profiling of GSK-3β knockdown organoids we identified additional candidate target genes of the inhibitor, among others FOXM1 and EGF. This gives evidence of Wnt pathway independent regulatory mechanisms of alveolar specification. Following influenza A virus (IAV) infection organoids showed a similar response as lung tissue explants which confirms their suitability for studies of sequelae of pathogen-host interaction
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