2,068 research outputs found

    Manejo químico de adubos verdes para sucessão da cana-de-açúcar em sistema de cultivo mínimo

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    Studies on chemical management of green manure are scarce in national literature. This work aimed to evaluate the herbicides efficiency in chemical control of green manure used in succession with sugarcane crop, in minimum cultivation system. Two experiments were conducted with Mucuna aterrima and Crotalaria spectabilis species, arranged in a randomized complete block design with 19 treatments and four replicates. The treatments were composed by three distinct rate for herbicides: glyphosate+2,4-D+carfentrazone-ethyl; glyphosate+2,4-D; glyphosate+MSMA; 2,4-D+carfentrazone-ethyl; 2,4-D; 2,4-D+picloran and check without herbicide application. Chemical control with tank mixture between glyphosate+2,4-D+carfentrazone-ethyl and glyphosate+2,4-D were the outstanding alternatives on of M. aterrima and C. spectabilis management, allowing the possibility of succession planting sugar cane crop in minimum cultivation system, with economy of operations of plowing and harrowing.Estudos referentes a manejo químico de adubos verdes são escassos na literatura nacional. O trabalho teve com objetivo avaliar a eficiência de herbicidas no controle químico dos adubos verdes para sucessão com a cultura da cana-de-açúcar, em sistema de cultivo mínimo. Foram conduzidos dois ensaios com as espécies Crotalaria spectabilis e Mucuna aterrima em delineamento de blocos ao acaso com 19 tratamentos e quatro repetições. Os tratamentos foram constituídos de três dosagens distintas para os herbicidas: glyphosate + 2,4-D + carfentrazone-ethyl; glyphosate + 2,4-D; glyphosate + MSMA; 2,4-D + carfentrazone; 2,4-D; 2,4-D + picloran e uma testemunha sem aplicação. O controle químico com as misturas em tanque de glyphosate + 2,4-D + carfentrazone-ethyl e glyphosate + 2,4-D foram às alternativas com maior sucesso no manejo de M. aterrima e C. spectabilis, as quais podem viabilizar a possibilidade de sucessão do plantio da cana-de-açúcar em sistema de cultivo mínimo, com economia das operações de aração e gradagem

    Períodos de interferência de plantas daninhas na cultura do feijoeiro comum

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    This work aimed to determine weed interference on common bean crop productivity (Phaseolus vulgaris). The experiment was carried out in the agricultural crop-year of 2016/2017 in the county of Curitibanos, SC. The experimental design was a randomized block design with twelve treatments and five replications. The treatments were arranged in a factorial scheme 2 x 6. The first factor was represented by two interference models being a period of coexistence or period before interference (PAI), and another control period or total period of interference prevention (PTPI). The second factor consisted of 6 growing seasons in which the crop cohabited or was kept free of the presence of weeds (0, 7, 15, 30, 60, 102 days after emergence - DAE). The following parameters were evaluated: the plant stand count at 2.0 meters, number of pods per plant, the mass of a hundred grains, and the final yield. Our results demonstrated that the critical period of interference prevention (PCPI) was situated between 5 and 54 DAE. Weed interference during the whole cycle of the bean crop reduced the number of plants, the number of pods per plant, and the yield of the cv. IPR Tangará, being the last variable in 80.4%.Este trabalho foi realizado com o objetivo de verificar os períodos de interferência de plantas daninhas sobre os componentes de rendimento e a produtividade da cultura do feijoeiro comum, cv. IPR Tangará, cultivado em Curitibanos-SC. O experimento foi conduzido no ano agrícola de 2016/17, no município de Curitibanos. O delineamento experimental utilizado foi o de blocos casualizados com 12 tratamentos e cinco repetições. Os tratamentos foram dispostos em esquema fatorial 2 x 6. O primeiro fator foi representado por dois modelos de interferência sendo um período de convivência ou período anterior à interferência (PAI) e outro período de controle ou período total de prevenção a interferência (PTPI). O segundo fator foi composto por seis épocas crescentes em que a cultura conviveu ou foi mantida livre da presença das plantas daninhas (0, 7, 15, 30, 60, 102 dias após a emergência - DAE). Foram avaliados o estande de plantas em 2,0 metros, o número de vagens por planta, a massa de cem grãos e a produtividade. O período crítico de prevenção à interferência (PCPI) situou-se entre 5 e 54 DAE. A interferência das plantas daninhas durante todo o ciclo do feijoeiro reduziu o estande de plantas, o número de vagens por planta e a produtividade da cultivar IPR Tangará, sendo que esta última variável apresentou redução de 80,4%

    Seletividade de formulações de nicosulfuron para híbridos de milho em função da época da adubação nitrogenada

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    Aimed in the present work to evaluate the interaction effect between periods of nitrogen coverage fertilization and different formulations of nicosulfuron herbicide over the selectivity to 2B-710 and 30K73 corn hybrids. Two experiments were conducted, simultaneously, with corn seedlings in V3 and V6 stages using treatments disposed in a factorial scheme 2x4+1, where the first factor was composed by two nicosulfuron formulations (18.8 g ha-1) (SansonTM and AccentTM) in mixture with atrazine (1250 g ha-1) and the second factor constituted by four periods of nitrogen coverage fertilization (67.5 kg N ha-1), represented by 0, 3, 6 and 9 days after herbicide application (DAAH); and an additional check without herbicide application. 2B-710 and 30K73 corn hybrids showed variable selectivity in relation to nicosulfuron herbicide application, with the major effects and symptoms of phytotoxicity occurring when nitrogen fertilization was performed in coverage in the same day of SansonTM formulation applying for V3 stage and three days from applying AccentTM to V6 stage. Objetivou-se no presente trabalho avaliar o efeito da interação entre as épocas de adubação nitrogenada de cobertura e diferentes formulações do herbicida nicosulfuron sobre a seletividade aos híbridos de milho 2B-710 e 30K73. Dois experimentos foram conduzidos simultaneamente, com plantas de milho em estádios V3 e V6, sendo os tratamentos dispostos em esquema fatorial 2x4+1, onde o primeiro fator foi constituído por duas formulações de nicosulfuron (18,8 g ha-1) (Sanson® e Accent®) em mistura com atrazine (1250 g ha-1); o segundo fator por quatro épocas de adubação nitrogenada (67,5 kg N ha-1), representadas por 0, 3, 6 e 9 dias após a aplicação do herbicida (DAAH); mais uma testemunha adicional sem aplicação de herbicidas. Os híbridos de milho 2B-710 e 30K73 apresentaram seletividade variável quanto à aplicação de nicosulfuron, sendo que os maiores efeitos e sintomas da fitointoxicação ocorreram quando a adubação nitrogenada foi realizada em cobertura no mesmo dia da aplicação da formulação Sanson® para o estádio V3, e aos três dias da aplicação de Accent® para o estádio V6

    Gradenigo's Syndrome: Beyond the Classical Triad of Diplopia, Facial Pain and Otorrhea

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    We report a case of a non-Hodgkin's lymphoma in a young woman presenting with an abdominal mass and an unusual instance of cranial nerve palsies mimicking Gradenigo's syndrome. This condition is characterized by a triad of otorrhea, facial pain and diplopia, related to otitis media in the pre-antibiotic era. Incomplete and atypical clinical features of Gradenigo's syndrome have been described and noninfectious causes may mimic this condition. Careful clinical history and physical examination, including neuroimaging, are necessary to make a differential diagnosis

    Identification of strain-specific B-cell epitopes in Trypanosoma cruzi using genome-scale epitope prediction and high-throughput immunoscreening with peptide arrays

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    BACKGROUND: The factors influencing variation in the clinical forms of Chagas disease have not been elucidated; however, it is likely that the genetics of both the host and the parasite are involved. Several studies have attempted to correlate the T. cruzi strains involved in infection with the clinical forms of the disease by using hemoculture and/or PCR-based genotyping of parasites from infected human tissues. However, both techniques have limitations that hamper the analysis of large numbers of samples. The goal of this work was to identify conserved and polymorphic linear B-cell epitopes of T. cruzi that could be used for serodiagnosis and serotyping of Chagas disease using ELISA. METHODOLOGY: By performing B-cell epitope prediction on proteins derived from pair of alleles of the hybrid CL Brener genome, we have identified conserved and polymorphic epitopes in the two CL Brener haplotypes. The rationale underlying this strategy is that, because CL Brener is a recent hybrid between the TcII and TcIII DTUs (discrete typing units), it is likely that polymorphic epitopes in pairs of alleles could also be polymorphic in the parental genotypes. We excluded sequences that are also present in the Leishmania major, L. infantum, L. braziliensis and T. brucei genomes to minimize the chance of cross-reactivity. A peptide array containing 150 peptides was covalently linked to a cellulose membrane, and the reactivity of the peptides was tested using sera from C57BL/6 mice chronically infected with the Colombiana (TcI) and CL Brener (TcVI) clones and Y (TcII) strain. FINDINGS AND CONCLUSIONS: A total of 36 peptides were considered reactive, and the cross-reactivity among the strains is in agreement with the evolutionary origin of the different T. cruzi DTUs. Four peptides were tested against a panel of chagasic patients using ELISA. A conserved peptide showed 95.8% sensitivity, 88.5% specificity, and 92.7% accuracy for the identification of T. cruzi in patients infected with different strains of the parasite. Therefore, this peptide, in association with other T. cruzi antigens, may improve Chagas disease serodiagnosis. Together, three polymorphic epitopes were able to discriminate between the three parasite strains used in this study and are thus potential targets for Chagas disease serotyping

    Leucemia Linfoblástica Aguda (LLA) na população pediátrica: marcadores moleculares e implicações terapêuticas

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    A Leucemia Linfoblástica Aguda (LLA) é uma forma comum de câncer pediátrico, representando cerca de 80% dos casos de leucemia em crianças. A patologia é caracterizada pela proliferação descontrolada de células-tronco hematopoéticas na medula óssea, e avanços recentes na pesquisa genômica têm proporcionado uma compreensão mais profunda da complexidade molecular subjacente à doença. O presente estudo tem como objetivo oferecer uma visão abrangente dos principais marcadores moleculares e implicações terapêuticas associadas à LLA na população pediátrica. Este estudo, baseado em uma revisão sistemática da literatura científica, abrange o período de 2013 a 2023, utilizando as bases de dados PubMed (Medline), Cochrane Library e Scientific Electronic Library Online (SciELO). Marcadores moleculares preponderantes, como rearranjos cromossômicos específicos (t(12;21), t(1;19), t(9;22)), mutações genéticas distintivas (ETV6-RUNX1, E2A-PBX1, TP53) e amplificação do gene BCR-ABL1, têm sido objeto de estudo aprofundado. Esses marcadores desempenham um papel crucial na estratificação de risco e prognóstico, permitindo uma abordagem mais personalizada no tratamento da LLA em crianças. As implicações terapêuticas derivadas desses marcadores são vastas, destacando a promissora era das terapias direcionadas. Terapias específicas para mutações, como aquelas direcionadas à mutação BCR-ABL1, e inovações em imunoterapia estão moldando o cenário do tratamento da LLA, proporcionando resultados mais eficazes e menos tóxicos. Os resultados destacam a eficácia das terapias direcionadas e a necessidade contínua de pesquisa para otimizar a intervenção terapêutica, melhorar a qualidade de vida dos pacientes pediátricos afetados pela LLA e explorar novas facetas do tratamento. Em conclusão, este artigo fornece uma análise aprofundada dos marcadores moleculares e terapias associadas à LLA na população pediátrica, destacando avanços significativos e delineando áreas para investigação futura

    EpIG‐DB: A database of vascular epiphyte assemblages in the Neotropics

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    Vascular epiphytes are a diverse and conspicuous component of biodiversity in tropical and subtropical forests. Yet, the patterns and drivers of epiphyte assemblages are poorly studied in comparison with soil‐rooted plants. Current knowledge about diversity patterns of epiphytes mainly stems from local studies or floristic inventories, but this information has not yet been integrated to allow a better understanding of large‐scale distribution patterns. EpIG‐DB, the first database on epiphyte assemblages at the continental scale, resulted from an exhaustive compilation of published and unpublished inventory data from the Neotropics. The current version of EpIG‐DB consists of 463,196 individual epiphytes from 3,005 species, which were collected from a total of 18,148 relevés (host trees and ‘understory’ plots). EpIG‐DB reports the occurrence of ‘true’ epiphytes, hemiepiphytes and nomadic vines, including information on their cover, abundance, frequency and biomass. Most records (97%) correspond to sampled host trees, 76% of them aggregated in forest plots. The data is stored in a TURBOVEG database using the most up‐to‐date checklist of vascular epiphytes. A total of 18 additional fields were created for the standardization of associated data commonly used in epiphyte ecology (e.g. by considering different sampling methods). EpIG‐DB currently covers six major biomes across the whole latitudinal range of epiphytes in the Neotropics but welcomes data globally. This novel database provides, for the first time, unique biodiversity data on epiphytes for the Neotropics and unified guidelines for future collection of epiphyte data. EpIG‐DB will allow exploration of new ways to study the community ecology and biogeography of vascular epiphytes

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
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