12 research outputs found

    TOXICITY OF PRE-EMERGENT HERBICIDES APPLIED VIA IRRIGATION WATER IN EUCALYPTUS PLANTATION

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    The objective of this study was to evaluate the toxicity of pre-emergent herbicides to eucalyptus plants and weed control efficiency when applied via irrigation water in crop implementation. The experiment was conducted under field conditions, using the experimental randomized block design for each herbicide, in a 5 x 2 bifactorial scheme, with four replications, considering the five evaluated herbicide doses as factors (isoxaflutole – 0; 75; 105; 135 and 165 g a.i. ha-1; flumioxazin – 0; 70; 90; 110 and 130 g a.i. ha-1; sulfentrazone – 0; 400; 600; 800 and 1000 g a.i. ha-1), besides two forms of application (directly on the plant and only on the soil). The treatments were applied manually 20 days after the seedlings were planted, using a watering can. Eucalyptus intoxication percentage, plant height, stem diameter, Falker chlorophyll index, leaf number, leaf area and shoot dry mass were evaluated. Weeds present in the useful area around the planting holes were identified and quantified to determine the plant density in the area sampled per treatment. It was found that only sulfentrazone caused plant intoxication symptoms, despite not influencing eucalyptus development. Isoxaflutole, regardless of application form, and flumioxazin, applied directly on the plants, were selective to the crop, providing at the highest doses (165 and 130 a.i. ha-1, respectively) efficient weed control and increment in initial eucalyptus growth

    Eficiência e toxicidade do oxyfluorfen em água de irrigação na implantação a campo do gênero Eucalyptus

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    This research aimed to evaluate the toxicity of oxyfluorfen doses applied in pre-emergence via irrigation water in the implantation of eucalyptus crop, clone VCC865 (hybrid Eucalyptus urophylla x Eucalyptus grandis), in addition to its effectiveness in weed control. The experiment was conducted under field conditions, in experimental design in randomized block, with four replications, in a 5 x 2 x 2 factorial scheme: five doses of oxyfluorfen herbicide (0, 360, 720, 1080 and 1440 g a.i. ha-1), two forms of application (on the plant and on the soil) and two volumes of irrigation water (5 and 10 L). The treatments were applied manually 15 days after planting the seedlings using a watering can. Eucalyptus intoxication percentage, plant height, collar diameter, leaf number, leaf area, shoot dry mass, relative chlorophyll content, stomatal conductance, internal CO2  concentration, photosynthetic rate and respiration rate were evaluated. Weeds present in the useful area of the planting holes were identified and quantified to determine plant density in the sampled area by treatment. In the area of implantation of the eucalyptus, 27 species of weeds were identified, belonging to 23 genera and 11 botanical families, with greater occurrence of Chenopodium carinatum, Blainvillea biaristata and Urochloa decumbens. The oxyfluorfen in the irrigation water, regardless of the application form and the volume of irrigation water volume, was selective for the crop at the doses evaluated. The highest doses (1080 and 1440 g a.i. ha-1) effectively controlled pre-emergence of weed growth, which increased initial growth of the eucalyptus plants, mainly in the leaf number, leaf area and accumulation of shoot dry mass.O objetivo desta pesquisa foi avaliar a toxicidade de doses do herbicida oxyfluorfen aplicado em pré-emergência via água de irrigação na implantação da cultura do eucalipto, clone VCC865 (híbrido de Eucalyptus urophylla x Eucalyptus grandis), além de sua eficácia no controle de plantas daninhas. O experimento foi conduzido em condições de campo, em delineamento experimental em blocos casualizados, com quatro repetições, em esquema fatorial 5 x 2 x 2, sendo cinco doses do herbicida oxyfluorfen (0; 360; 720; 1080 e 1440 g i.a. ha-1), dois modos de aplicação (sobre a planta e sobre o solo) e dois volumes da água de irrigação (5 e 10 litros). Os tratamentos foram aplicados manualmente 15 dias após o plantio das mudas com auxílio de um regador. Foram realizadas avaliações de porcentagem visual de intoxicação, altura de plantas, diâmetro do coleto, número de folhas, área foliar total, massa seca da parte aérea, teor relativo de clorofila, condutância estomática, concentração interna de CO2, taxa fotossintética e taxa de transpiração. As plantas daninhas presentes na área útil do entorno das covas de plantio foram identificadas e quantificadas, para determinação da densidade de plantas na área amostrada por tratamento. Foram identificadas na área de implantação do eucalipto 27 espécies de plantas daninhas, pertencentes a 23 gêneros e 11 famílias botânicas, com maior ocorrência de Chenopodium carinatum, Blainvillea biaristata e Urochloa decumbens. O oxyfluorfen na água de irrigação, independente da forma de aplicação e o volume de água de irrigação, mostrou-se seletivo à cultura nas doses avaliadas, promovendo nas maiores doses (1080 e 1440 g i.a. ha-1) eficiente controle em pré-emergência das plantas daninhas e aumento no crescimento inicial do eucalipto, principalmente no número de folhas, área foliar e acúmulo de massa seca da parte aérea

    Genetic comparison of sickle cell anaemia cohorts from Brazil and the United States reveals high levels of divergence

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    Genetic analysis of admixed populations raises special concerns with regard to study design and data processing, particularly to avoid population stratification biases. The point mutation responsible for sickle cell anaemia codes for a variant hemoglobin, sickle hemoglobin or HbS, whose presence drives the pathophysiology of disease. Here we propose to explore ancestry and population structure in a genome-wide study with particular emphasis on chromosome 11 in two SCA admixed cohorts obtained from urban populations of Brazil (Pernambuco and Sao Paulo) and the United States (Pennsylvania). Ancestry inference showed different proportions of European, African and American backgrounds in the composition of our samples. Brazilians were more admixed, had a lower African background (43% vs. 78% on the genomic level and 44% vs. 76% on chromosome 11) and presented a signature of positive selection and Iberian introgression in the HbS region, driving a high differentiation of this locus between the two cohorts. The genetic structures of the SCA cohorts from Brazil and US differ considerably on the genome-wide, chromosome 11 and HbS mutation locus levels9CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP8367/2011-1; 150398/2013-1; 304455/2012-1; 310938/2014-7; 305218/2017-48367/2011-1; 150398/2013-1; 304455/2012-1; 310938/2014-7; 305218/2017-42008/57441-0; 2014/00984-3; 2012/06438-5; 2015/13152-9; 2008/10596-

    Controles alternativos de fungos em sementes de Gossypium hirsutum L. e avaliação da qualidade fisiológica / Alternatives controls of fungi in Gossypium hirsutum L. seeds evaluation of the physiological quality

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    O algodoeiro (Gossypium hirsutum L.) é acometido por diversas doenças que, em sua maioria, são transmitidas por sementes, resultando em perdas significativas na produção. Com isso, os tratamentos alternativos em sementes tornam-se, um parâmetro imprescindível no manejo e controle destas doenças. Por isso, objetivou-se determinar a qualidade sanitária e fisiológica de dois lotes de sementes de algodoeiro Lote 1: Cultivar BRS Aroeira e lote 2: Cultivar BRS 416, ambas submetidas aos tratamentos com óleos essenciais de Pimpinella anisum, Mentha piperita, e Dianthus caryophyllus nas concentrações de 1, 2 e 3% e ao tratamento asséptico em diferentes combinações. Em todos os testes, a testemunha correspondeu apenas na imersão das sementes em água destilada esterilizada (ADE). Para os tratamentos que utilizaram os óleos essenciais, as sementes foram imersas por 5 minutos nos tratamentos e o fungicida aplicado diretamente sobre a superfície das sementes O delineamento foi inteiramente casualizado. Os resultados foram submetidos à análise de variância e quando significativos. Para a interação não significativa, os dados qualitativos foram submetidos ao teste de Scott-Knott (p?0,05) no Programa Estatístico SISVAR®. Os óleos essenciais de Mentha piperita e Dianthus caryophyllus nas concentrações de 1, 2 e 3% são eficientes na redução dos fungos: Aspergillus sp., Aspergillus niger, Penicillium sp. e Periconia sp. O fungo Fusarium sp. foi reduzido quando utilizou-se o óleo de Pimpinella anisum nas concentrações de 1, 2 e 3%. O uso do hipoclorito de sódio nas concentrações de 1 e 3% são eficientes na redução de Aspergillus sp., Aspergillus niger, Penicillium sp., Periconia sp e Fusarium sp

    Global gene expression reveals an increase of HMGB1 and APEX1 proteins and their involvement in oxidative stress, apoptosis and inflammation pathways among beta-thalassaemia intermedia and major phenotypes

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    Beta-thalassaemia (BT) is classified according to blood transfusion requirement as minor (BTMi), intermedia (BTI) and major (BTM). BTM is the most severe form, requiring regular transfusions while transfusion need is only occasional in BTI. Differential gene expression between patients has not been assessed so far. Here, we evaluated the global gene expression profiles during differentiation of human erythroid cells of two patients carrying the same mutation [CD39, (C -> T)], though displaying different phenotypes (BTI and BTM). Considering the role of reactive oxygen species (ROS) in the pathophysiology of thalassaemia, we focused on differentially expressed genes involved in metabolic pathways triggered by ROS, such as inflammation and apoptosis, and, from these, we selected the Apurinic/Apyrimidinic Endodeoxyribonuclease 1 (APEX1) and High Mobility Group Box1 (HMGB1) genes, whose role in BT is not well established. An in-depth expression analysis of transcriptional and protein levels in patients carrying a range of mutations associated with BT phenotypes indicated that APEX1 was increased in both BTI and BTM. Furthermore, higher amounts of HMGB1 was found in the plasma of BTI patients. Our findings suggest that these proteins have important roles in BT and could represent new targets for further studies aiming to improve the management of the disease1864608619CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãosem informação2011/50358-

    Whole-exome sequencing indicates FLG2 variant associated with leg ulcers in Brazilian sickle cell anemia patients

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    Although sickle cell anemia results from homozygosity for a single mutation at position 7 of the beta-globin chain, the clinical aspects of this condition are very heterogeneous. Complications include leg ulcers, which have a negative impact on patients' quality of life and are related to the severity of the disease. Nevertheless, the complex pathogenesis of this complication has yet to be elucidated. To identify novel genes associated with leg ulcers in sickle cell anemia, we performed whole-exome sequencing of extreme phenotypes in a sample of Brazilian sickle cell anemia patients and validated our findings in another sample. Our discovery cohort consisted of 40 unrelated sickle cell anemia patients selected based on extreme phenotypes: 20 patients without leg ulcers, aged from 40 to 61 years, and 20 with chronic leg ulcers. DNA was extracted from peripheral blood leukocytes and used for whole-exome sequencing. After the bioinformatics analysis, eight variants were selected for validation by Sanger sequencing and TaqMan (R) genotyping in 293 sickle cell anemia patients (153 without leg ulcers) from two different locations in Brazil. After the validation, Fisher's exact test revealed a statistically significant difference in a stop codon variant (rs12568784 G/T) in the FLG2 gene between the GT and GG genotypes (P = 0.035). We highlight the importance of rs12568784 in leg ulcer development as this variant of the FLG2 gene results in impairment of the skin barrier, predisposing the individual to inflammation and infection. Additionally, we suggest that the remaining seven variants and the genes in which they occur could be strong candidates for leg ulcers in sickle cell anemia. Impact statement To our knowledge, the present study is the first to use whole-exome sequencing based on extreme phenotypes to identify new candidate genes associated with leg ulcers in sickle cell anemia patients. There are few studies about this complication; the pathogenesis remains complex and has yet to be fully elucidated. We identified interesting associations in genes never related with this complication to our knowledge, especially the variant in the FLG2 gene. The knowledge of variants related with leg ulcer in sickle cell anemia may lead to a better comprehension of the disease's etiology, allowing prevention and early treatment options in risk genotypes while improving quality of life for these patients24411932939FAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2014/00984-3; 2015/24029-

    Brazilian Thalassemia Association protocol for iron chelation therapy in patients under regular transfusion

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    In the absence of an iron chelating agent, patients with beta-thalassemia on regular transfusions present complications of transfusion-related iron overload. Without iron chelation therapy, heart disease is the major cause of death; however, hepatic and endocrine complications also occur. Currently there are three iron chelating agents available for continuous use in patients with thalassemia on regular transfusions (desferrioxamine, deferiprone, and deferasirox) providing good results in reducing cardiac, hepatic and endocrine toxicity. These practice guidelines, prepared by the Scientific Committee of Associação Brasileira de Thalassemia (ABRASTA), presents a review of the literature regarding iron overload assessment (by imaging and laboratory exams) and the role of T2* magnetic resonance imaging (MRI) to control iron overload and iron chelation therapy, with evidence-based recommendations for each clinical situation. Based on this review, the authors propose an iron chelation protocol for patients with thalassemia under regular transfusions

    Endothelial Barrier Integrity Is Disrupted In Vitro by Heme and by Serum From Sickle Cell Disease Patients

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    Free extracellular heme has been shown to activate several compartments of innate immunity, acting as a danger-associated molecular pattern (DAMP) in hemolytic diseases. Although localized endothelial barrier (EB) disruption is an important part of inflammation that allows circulating leukocytes to reach inflamed tissues, non-localized/deregulated disruption of the EB can lead to widespread microvascular hyperpermeability and secondary tissue damage. In mouse models of sickle cell disease (SCD), EB disruption has been associated with the development of a form of acute lung injury that closely resembles acute chest syndrome (ACS), and that can be elicited by acute heme infusion. Here we explored the effect of heme on EB integrity using human endothelial cell monolayers, in experimental conditions that include elements that more closely resemble in vivo conditions. EB integrity was assessed by electric cell-substrate impedance sensing in the presence of varying concentrations of heme and sera from SCD patients or healthy volunteers. Heme caused a dose-dependent decrease of the electrical resistance of cell monolayers, consistent with EB disruption, which was confirmed by staining of junction protein VE-cadherin. In addition, sera from SCD patients, but not from healthy volunteers, were also capable to induce EB disruption. Interestingly, these effects were not associated with total heme levels in serum. However, when heme was added to sera from SCD patients, but not from healthy volunteers, EB disruption could be elicited, and this effect was associated with hemopexin serum levels. Together our in vitro studies provide additional support to the concept of heme as a DAMP in hemolytic conditions.Sao Paulo Research Foundation (FAPESP), grants 2016/14172-6 to EP, and 2014/00984-3 to FFC, respectively; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) Brazil; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior – Brasil (CAPES), finance code 001; and FAEPEX-UNICAM
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