605 research outputs found

    On the scattering amplitude in the Aharonov-Bohm gauge field

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    A general expression for the scattering amplitude of nonrelativistic spinless particles in the Aharonov-Bohm gauge potential is obtained within the time independent formalism. The result is valid also in the backward and forward directions as well as for any choice of the boundary conditions on the wave function at the flux tube position.Comment: 18 pages, plain TE

    Avaliação de cultivares de caupi para o consórcio com algodoeiro herbáceo

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    With the objective of evaluating cowpea (Vigna unguiculata (L.) Walp.) cultivars regarding their agronomic characteristics, seed quality and levels of competition with annual cotton (Gossypium hirsutum L., r. latifolium) in an intercropping production system, an experiment was carried out at Gurinhém, PB, Brazil, in 1983. Twelve cultivars of cowpea with different growth and fruiting characteristics were used in this experiment. Two rows of cowpea were planted between rows of cotton. The cowpeas were planted 35 cm (leaving five plants per meter of row) from the adjoining cotton rows with a 30 cm spacing between the two rows of cowpea. Cotton was grown in rows 1,0 m x 0,20 m apart. Only three cultivars of cowpea (Epace 6, 40 days and CNC x 105-5E) did not significantly reduce the yield of the annual cotton indicating that these cowpea cultivars are well adapted to an intercropping system with annual cotton. The twelve cultivars of cowpeas showed no statistical difference in yield grain and had an average of 489 kg/ha.Visando a avaliação de cultivares de caupi (Vigna unguiculata (L.) Walp.) com relação às características de produção, qualidade de grão e força de competição no consorciamento com o algodoeiro herbáceo (Gossypium hirsutum L., r. latifolium Hutch.), um experimento foi realizado no município de Gurinhém, Paraíba, em 1983. Testaram-se doze cultivares de caupi de hábitos de crescimento e ciclos diferentes, numa modalidade de consórcio em que se utilizaram fileiras duplas da leguminosa, espaçadas entre si de 0,30 cm e distanciadas das fileiras de algodão herbáceo de 0,35 cm, com uma densidade de cinco plantas por metro de fileira, objetivando maior pressão de competição do caupi sobre a malvácea. O algodão foi plantado no espaçamento de 1,0 m x 0,2 m. Apenas três cultivares de caupi (Epace 6, 40 dias e CNC x 105 - 5E) não reduziram significativamente o rendimento do algodão, mostrando sua melhor adaptação ao consórcio com o algodão herbáceo. As doze cultivares de caupi não diferiram entre si com relação à produtividade de grão, com uma média de 489 kg/ha

    Antioxidant activity and acute toxicity of Neoglaziovia variegata (Bromeliaceae)

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    Antioxidant activities of Neoglaziovia variegata were evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and β-carotene-linoleic acid bleaching and was compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The total phenolics content of the extracts was determined by the Folin-Ciocalteu method. Total flavonoid was also determined. The most significant total phenolic content was of 543.50 ± 9.38 mg of gallic acid equivalent/g for ethyl acetate extract (AcOEt), which presented the best antioxidant activity (IC50 5.08 ± 0.20 μg/ml) for DPPH scavenging. The acute toxicity of Nv-EtOH was performed 2.0 g/kg intraperitoneally and 5.0 g/kg orally in mice. No mortality and no toxicity signs were observed, indicating low toxicity of the extract. Blood was removed after 14 days for laboratory analysis of hematological and biochemical parameters. Alterations of aspartate aminotransferase (AST) and creatinine were observed. The data obtained showed that the doses induced microscopic alterations in the liver and kidney. In conclusion, the Nv-EtOH can be considered of low toxicity.Keywords: Antioxidant activity, acute toxicity, Neoglaziovia variegata, Bromeliacea

    Avaliação da eficiência e desfecho da triagem e manejo da PKU no Estado de Sergipe, Brasil

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    Objectives: Phenylketonuria (PKU) was the first inherited metabolic disease known to cause mental retardation for which a newborn screening program (NBS) was developed. The objective of this study was to evaluate the effectiveness of PKU NBS and the management of cases in the northeastern Brazilian state of Sergipe (SE). Materials and methods: We reviewed the phenylalanine concentrations in filter-paper collected from the heel (PKUneo) of 43,449 newborns; blood concentrations obtained by venipuncture in the subjects with abnormal PKUneo; the children’s age at several phases of the program, the incidence of the disease from January 2007 to June 2008; and metabolic control of the patients. Results: The coverage of NBS/SE was 78.93%. The children’s age was 10 ± 7 days at PKUneo collection. Twelve children were recalled based on the PKUneo cutoff value at 28 ± 13 days. From these, the concentrations of phenylalanine collected by venipuncture were normal in five children. The incidence of hyperphenylalaninemia was 1/43,449, and of PKU was 1/8,690 (5 cases). One suspected subject died. Another death occurred in the cohort, in a confirmed PKU case. PKU treatment began within 51 ± 12 days of life. In the four patients under dietary phenylalanine restriction, metabolic control was often difficult. Conclusions: PKU NBS/SE has satisfactory coverage and adequate cutoff for recalling patients and diagnosis, but the onset of treatment is delayed, and follow-up metabolic control is frequently inadequate._________________________________________________________________________________________ RESUMO: Objetivos: A fenilcetonúria (PKU) foi a primeira causa metabólica hereditária de retardamento mental para a qual foi desenvolvido um programa de triagem em recém-nascidos (NBS). O objetivo deste estudo foi avaliar a eficácia do NBS para a PKU e o manejo dos casos em Sergipe (SE), Brasil. Materiais e métodos: Revisamos as concentrações de fenilalanina no filtro de papel coletado do calcanhar (PKUneo) de 43.449 recém-nascidos, suas concentrações de sangue obtidas por punção venosa em indivíduos com PKUneo anormal, a idade das crianças em diversas fases do programa, a incidência da doença no período de janeiro de 2007 a junho de 2008 e o controle metabólico dos pacientes. Resultados: A cobertura da NBS/SE foi de 78,93%. A idade das crianças era de 10 ± 7 dias na coleta de PKUneo. Doze crianças foram reconvocadas com base no ponto de corte de PKUneo aos 28 ± 13 dias de idade. Destas, as concentrações de fenilalanina por venipunctura foram normais em cinco. A incidência da hiperfenilalaninemia foi 1/43.449 e de PKU foi 1/8.690 (5 casos), e um indivíduo suspeito foi a óbito. Outro óbito ocorreu na coorte em um caso de PKU confirmado. O tratamento para a PKU começou com 51 ± 12 dias. Nos quatro pacientes sob restrição de fenilalanina alimentar, o controle metabólico foi frequentemente difícil. Conclusões: PKU NBS/SE apresenta uma cobertura satisfatória e ponto de corte adequado para reconvocação e diagnóstico, mas o início do tratamento é atrasado e o controle no seguimento é frequentemente inadequado

    Incidência do míldio em cebola sob adubação mineral e orgânica.

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    Analisou-se a relação entre adubação mineral e orgânica sobre a incidência de míldio (Peronospora destructor) em cebola (Allium cepa). O trabalho constituiu-se de dois experimentos localizados em Ituporanga, conduzidos entre agosto e dezembro de 1998. O experimento 1, com fontes orgânicas, constou dos tratamentos: esterco de suínos, esterco de aves, composto, esterco de peru e húmus, na dosagem de 75 kg/ha de N; esterco de suínos, na dosagem de 37,5 kg/ha de N; adubação mineral, 30-120-60 kg/ha de N-P2O5-K2O; 60-240-120 kg/ha de N-P2O5-K2O e testemunha sem adubação. O experimento 2 constou dos tratamentos: fontes minerais, 30-120-60 kg/ha de N-P2O5-K2O; 90-360-180 kg/ha de N-P2O5-K2O; 75 kg/ha de N; 225 kg/ha de N; 80 kg/ha de P2O5; 240 kg/ha de P2O5; 60 kg/ha de K2O; 180 kg/ha de K2O; esterco de suínos + fosfato natural, em três combinações, 7,9+0,1, 15,7+0,2 e 47,2+0,6 t/ha, respectivamente; testemunha sem adubação. Não houve diferença entre as fontes mineral e orgânica sobre a incidência de míldio. A relação entre nutrientes e doença foi variável entre datas de amostragem e distinta para fontes minerais e orgânicas

    Habitat use of the ocelot (Leopardus pardalis) in Brazilian Amazon

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    Amazonia forest plays a major role in providing ecosystem services for human and sanctuaries for wildlife. However, ongoing deforestation and habitat fragmentation in the Brazilian Amazon has threatened both. The ocelot is an ecologically important mesopredator and a potential conservation ambassador species, yet there are no previous studies on its habitat preference and spatial patterns in this biome. From 2010 to 2017, twelve sites were surveyed, totaling 899 camera trap stations, the largest known dataset for this species. Using occupancy modeling incorporating spatial autocorrelation, we assessed habitat use for ocelot populations across the Brazilian Amazon. Our results revealed a positive sigmoidal correlation between remote-sensing derived metrics of forest cover, disjunct core area density, elevation, distance to roads, distance to settlements and habitat use, and that habitat use by ocelots was negatively associated with slope and distance to river/lake. These findings shed light on the regional scale habitat use of ocelots and indicate important species–habitat relationships, thus providing valuable information for conservation management and land-use planning

    Genomic analysis and immune response in a murine mastitis model of vB_EcoM-UFV13, a potential biocontrol agent for use in dairy cows

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    Bovine mastitis remains the main cause of economic losses for dairy farmers. Mammary pathogenic Escherichia coli (MPEC) is related to an acute mastitis and its treatment is still based on the use of antibiotics. In the era of antimicrobial resistance (AMR), bacterial viruses (bacteriophages) present as an efficient treatment or prophylactic option. However, this makes it essential that its genetic structure, stability and interaction with the host immune system be thoroughly characterized. The present study analyzed a novel, broad host-range anti-mastitis agent, the T4virus vB-EcoM-UFV13 in genomic terms, and its activity against a MPEC strain in an experimental E. coli-induced mastitis mouse model. 4,975 Single Nucleotide Polymorphisms (SNPs) were assigned between vB-EcoM-UFV13 and E. coli phage T4 genomes with high impact on coding sequences (CDS) (37.60%) for virion proteins. Phylogenetic trees and genome analysis supported a recent infection mix between vB-EcoM-UFV13 and Shigella phage Shfl2. After a viral stability evaluation (e.g pH and temperature), intramammary administration (MOI 10) resulted in a 10-fold reduction in bacterial load. Furthermore, pro-inflammatory cytokines, such as IL-6 and TNF-\u3b1, were observed after viral treatment. This work brings the whole characterization and immune response to vB-EcoM-UFV13, a biocontrol candidate for bovine mastitis
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