5,597 research outputs found
Eficiência de Streptomyces spp. no biocontrole de fitopatógenos e promotor de crescimento vegetal
Rhizobacteria are very important agents for the promotion of plant growth due to the
production of metabolites. Among these rhizobacteria, Streptomyces have great
potential in producing several bioactive compounds. The objective of this work was to
characterize morphologically isolated Streptomyces spp., to evaluate phosphate
solubilization and the production of indole acetic acid (IAA), the compatibility between
Streptomyces spp. and Bradyrhizobium japonicum and the antagonistic activity to the
pathogenic fungi Curvularia lunata and Colletotrichum sp. In addition, the objective
was to select isolates of Streptomyces spp. to be used as inoculants for both
soybean and cowpea culture in the region and to evaluate the effect of the doses on
the crops. The results showed that the isolates of Streptomyces presented varied
phenotypic characteristics, and the isolate UFT-St07 presented index of phosphate
solubilization. Regarding the production of indole acetic acid, the best results were
obtained in the presence of the L-tryptophan inducer, and the best isolates observed
were UFT-St04 and UFT-St08. Regarding the compatibility between Streptomyces
spp. and inoculant B. japonicum, it was observed that the highest inhibition indices
were observed with the isolates UFT-St01 and UFT-St09. The UFT-St05 and UFTSt07
isolates showed a positive effect on the biocontrol of Curvularia lunata, and the
isolates UFT-St04 and UFT-St07 in the biotype of Colletotrichum sp. Regarding the
use of Streptomyces in the soybean crop, better results were observed with the
isolate UFT-St07. In the field experiment the different dosages of inoculant were
efficient in maintaining the final plant stand, and the best dose of Streptomyces MIX
(UFT-St03, UFT-St06 and UFT-St08) was 300 mL for every 50 kg of seed. Regarding
the bean culture, strain UFT-St03 was the one that presented the best results. In
addition, the best inoculant doses were 300 and 400 mL / 50 kg seeds for all
parameters evaluated. Thus, it was possible to observe that Streptomyces has
potential in the biocontrol of phytopathogenic fungi and can be used as biofertilizer
because they have potential in the growth and incorporation of biomass, besides
favoring productivity.Rizobactérias são agentes muito importantes para a promoção do crescimento de
plantas em razão da produção de metabólitos. Dentre estas rizobactérias, as
Streptomyces apresentam grande potencial em produzir diversos compostos
bioativos. Desse modo, o presente trabalho teve como objetivos, nos três capítulos
apresentados, caracterizar morfologicamente isolados de Streptomyces spp., avaliar
a solubilização de fosfato e a produção de ácido indol acético (AIA), a
compatibilidade entre Streptomyces spp. e Bradyrhizobium japonicum e a atividade
antagônica aos fungos patogênicos Curvularia lunata e Colletotrichum sp. Além
disso, objetivou selecionar isolados de Streptomyces spp., para serem utilizadas
como inoculantes tanto para a cultura da soja como para a cultura do feijão-caupi na
região e avaliar o efeito das doses sobre as culturas. Os resultados obtidos
indicaram que os isolados de Streptomyces apresentaram características fenotípicas
variadas, sendo que o isolado UFT-St07 apresentou índice de solubilização de
fosfato. Em relação à produção de ácido indol acético, os melhores resultados foram
obtidos na presença do indutor L-triptofano, e os melhores isolados observados
foram UFT-St04 e UFT-St08. Quanto à compatibilidade entre Streptomyces spp. e o
inoculante B. japonicum, observou-se que os maiores índices de inibição foram
observados com os isolados UFT-St01 e UFT-St09. Os isolados UFT-St05 e UFTSt07
apresentaram efeito positivo no biocontrole de Curvularia lunata., e os isolados
UFT-St04 e UFT-St07 no biocontrole de Colletotrichum sp. Quanto à utilização de
Streptomyces na cultura da soja melhores resultados foram observados com o
isolado UFT-St07. No experimento em campo as diferentes dosagens de inoculante
mostraram-se eficientes na manutenção do estande final de plantas, sendo que a
melhor dose do MIX de Streptomyces (UFT-St03, UFT-St06 e UFT-St08) foi de 300
mL para cada 50 kg de semente. Quanto à cultura de feijão, a estirpe UFT-St03 foi a
que apresentou melhores resultados. Além disso, as melhores doses de inoculante
foram de 300 e 400 mL/50 kg sementes para todos os parâmetros avaliados. Dessa
forma, foi possível observar que as Streptomyces tem potencial no biocontrole de
fungos fitopatogênicos e podem ser utilizadas como biofertilizante por apresentarem
potencial no crescimento e incorporação de biomassa, além de favorecer a
produtividade
Locating the VHE source in the Galactic Centre with milli-arcsecond accuracy
Very high-energy gamma-rays (VHE; E>100 GeV) have been detected from the
direction of the Galactic Centre up to energies E>10 TeV. Up to now, the origin
of this emission is unknown due to the limited positional accuracy of the
observing instruments. One of the counterpart candidates is the super-massive
black hole (SMBH) Sgr A*. If the VHE emission is produced within ~10^{15} cm
~1000 r_G (r_G=G M/c^2 is the Schwarzschild radius) of the SMBH, a decrease of
the VHE photon flux in the energy range 100--300 GeV is expected whenever an
early type or giant star approaches the line of sight within ~ milli-arcseconds
(mas). The dimming of the flux is due to absorption by pair-production of the
VHE photons in the soft photon field of the star, an effect we refer to as
pair-production eclipse (PPE). Based upon the currently known orbits of stars
in the inner arcsecond of the Galaxy we find that PPEs lead to a systematic
dimming in the 100--300 GeV band at the level of a few per cent and lasts for
several weeks. Since the PPE affects only a narrow energy band and is well
correlated with the passage of the star, it can be clearly discriminated
against other systematic or even source-intrinsic effects. While the effect is
too small to be observable with the current generation of VHE detectors,
upcoming high count-rate experiments like the Cherenkov telescope array (CTA)
will be sufficiently sensitive. Measuring the temporal signature of the PPE
bears the potential to locate the position and size of the VHE emitting region
within the inner 1000 r_G or in the case of a non-detection exclude the
immediate environment of the SMBH as the site of gamma-ray production
altogether.Comment: 7 pages, published in MNRAS 402, pg. 1342-134
DESENVOLVIMENTO DE MÉTODO PARA DETERMINAÇÃO DE CHUMBO EM AMOSTRAS DE BATOM
Sendo o quarto maior mercado consumidor de produtos de higiene pessoal, perfumaria e cosméticos com uma movimentação de US$ 229 bilhões, o Brasil representa 4,3% do mercado mundial, ficando atrás apenas de Estados Unidos, China e Japão. Mesmo com a retração econômica do real de -5,6% no ano de 2021 houve um aumento no volume de vendas deste setor de 3,4% em relação ao ano de 2020, sendo o segundo país que mais lança produtos anualmente (ABIHPEC, 2022)
Role of exchange interaction in self-consistent calculations of endohedral fullerenes
Results of the self-consistent calculation of electronic structure of
endohedral fullerene Ar@C within the Hartree-Fock and the local density
approximations are presented. Hartree-Fock approximation is used for the
self-consistent description for the first time. It is shown that the accurate
account of the exchange interaction between all electrons of the compound leads
to the significant modification of the atomic valent shell which causes the
noticeable charge redistribution inside the endohedral compound.Comment: 5 figures, Proceedings of the 5th Conference on Elementary Processes
in Atomic Systems (CEPAS 2011), submitted to Nuclear Instruments and Methods
in Physics Research Section
DETERMINAÇÃO DE CLORO RESIDUAL EMPREGANDO IMAGENS DIGITAIS
Com o aumento da população e sua concentração em grandes cidades, os sistemas de distribuição e desinfecção de água se tornaram cada vez mais complexos e necessários. A poluição hídrica exige o desenvolvimento de métodos para tornar a água potável, sendo um dos mais utilizados a cloração, que consiste na adição de cloro como agente desinfectante que inativa e destrói organismos nocivos (BARROS, 2018)
OSTVARENJE URAVNOTEŽENOG PRISTUPA IZMEĐU ŽRTVE I PRIJESTUPNIKA: INTEGRIRANJE PROAKTIVNOG PRISTUPA PREMA ŽRTVI
The Mediation and Reparation Program (MRP) was from the outset set up with the mission of serving both victims’ and offenders’ needs alike, that is to say, informed by a balanced approach between victim and offender in accordance with the restorative justice (RJ) principles.
Concerned with the risk of secondary victimisation, the scheme has traditionally observed the protective approach; therefore as a general rule, with serious crimes we have followed the offender-initiated model. However, the experience gathered has shown that such practice was not fully in line with our stated mission as victims were having more limited access to the scheme compared to offenders.
The aim of this paper is to share the process that has led a team of practitioners to reflect on our practice and review the protective approach in place. To that end, the combination of factors we have identified to be at the root of this transformation will be analysed, and the key changes introduced in order to improve victims’ access will also be outlined.Program posredovanja (medijacije) i reparativne pravde od samoga je početka pokrenut s misijom jednakomjernog služenja potrebama žrtava i počinitelja, odnosno, utemeljen je na uravnoteženom pristupu između žrtve i počinitelja, u skladu s načelima restorativne pravde.
Zaokupljen rizikom od sekundarne viktimizacije, program kao i uvijek slijedi načela zaštitničkog pristupa; stoga smo, kao opće pravilo, kod teških zločina slijedili model koji se pokreće na zahtjev počinitelja. No prikupljeno je iskustvo pokazalo da takva praksa nije sasvim u skladu s našom misijom jer su žrtve, u usporedbi s počiniteljima, imale ograničeniji pristup programu.
Cilj ovoga rada je predstavljanje procesa koji je skupinu praktičara navodio na razmišljanje o našoj praksi i pregledavanje ustanovljenog zaštitničkog pristupa. U tu će se svrhu analizirati kombinacija čimbenika za koje smo identificirali da se nalaze u korijenu takve transformacije, te će se također navesti ključne promjene koje su uvedene kako bi se žrtvama olakšao pristup
Are Known Cyanotoxins Involved in the Toxicity of Picoplanktonic and Filamentous North Atlantic Marine Cyanobacteria?
Eight marine cyanobacteria strains of the genera Cyanobium, Leptolyngbya, Oscillatoria, Phormidium, and Synechococcus were isolated from rocky beaches along the Atlantic Portuguese central coast and tested for ecotoxicity. Strains were identified by morphological characteristics and by the amplification and sequentiation of the 16S rDNA. Bioactivity of dichloromethane, methanol and aqueous extracts was assessed by the Artemia salina bioassay. Peptide toxin production was screened by matrix assisted laser desorption/ionization time of flight mass spectrometry. Molecular analysis of the genes involved in the production of known cyanotoxins such as microcystins, nodularins and cylindrospermopsin was also performed. Strains were toxic to the brine shrimp A. salina nauplii with aqueous extracts being more toxic than the organic ones. Although mass spectrometry analysis did not reveal the production of microcystins or other known toxic peptides, a positive result for the presence of mcyE gene was found in one Leptolyngbya strain and one Oscillatoria strain. The extensive brine shrimp mortality points to the involvement of other unknown toxins, and the presence of a fragment of genes involved in the cyanotoxin production highlight the potential risk of cyanobacteria occurrence on the Atlantic coast
Genetic characterization of morphologically variant strains of Paracoccidioides brasiliensis
Molecular characterization of Paracoccidioides brasiliensis variant strains that had been preserved under mineral oil for decades was carried out by random amplified polymorphic DNA analysis (RAPD). On P. brasiliensis variants in the transitional phase and strains with typical morphology, RAPD produced reproducible polymorphic amplification products that differentiated them. A dendrogram based on the generated RAPD patterns placed the 14 P. brasiliensis strains into five groups with similarity coefficients of 72%. A high correlation between the genotypic and phenotypic characteristics of the strains was observed. A 750 bp-RAPD fragment found only in the wild-type phenotype strains was cloned and sequenced. Genetic similarity analysis using BLASTx suggested that this RAPD marker represents a putative domain of a hypothetical flavin-binding monooxygenase (FMO)-like protein of Neurospora crassa.FiocruzBritish Council Progra
A comparison of three dual drainage models: shallow water vs local inertial vs diffusive wave
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