Endophytic fungi community in eremanthus erythropappus tree from anthropogenic and natural areas of Minas Gerais.

It is know that many plants live in symbiosis with microorganisms that can be found on their interior, the endophytes. Environment and tissue type are modulating factors of this community, in which most of these microorganisms produce important antimicrobial molecules and they may be powerful biocontrol agents in agriculture. Thus, the aim of this study was to evaluate the community of Endophytic fungi from Eremanthus erythropappus in anthropogenic and natural areas (with human interaction, natural habitat and planned planting) of Minas Gerais State, Brazil, through cultivation-based approach and verify their antimicrobial activity against phytopathogenic fungal and pathogenic bacteria. The endophytic fungi isolated were identified by sequencing of the ITS region and subjected an in vitro antagonism test. The antagonisms that show antibiosis were submitted to tests on split plates to verify the volatile compound production. In the pairing testes, the endophytic fungi of the genera Cryptosporiopsis, Diaporthe, Xylaria, Paraconiothyrium and Camarosporium presented antibiosis against phytopathogenic fungi by releasing compounds in the medium. To our knowledge, this paper is the first report on the isolation of twelve genera fungi in E. erythropappus besides verifying their antagonist capacity, which opens the way for discovery of bioactive substances produced by endophytic fungi that inhibit pathogens

Magnetic anisotropy in antiferromagnetic hexagonal MnTe

Antiferromagnetic hexagonal MnTe is a promising material for spintronic devices relying on the control of antiferromagnetic domain orientations. Here we report on neutron diffraction, magnetotransport, and magnetometry experiments on semiconducting epitaxial MnTe thin films together with density functional theory (DFT) calculations of the magnetic anisotropies. The easy axes of the magnetic moments within the hexagonal basal plane are determined to be along ⟨1¯100⟩ directions. The spin-flop transition and concomitant repopulation of domains in strong magnetic fields is observed. Using epitaxially induced strain the onset of the spin-flop transition changes from ∼2 to ∼0.5 T for films grown on InP and SrF2 substrates, respectively

A Discussion on Supersymmetric Cosmic Strings with Gauge-Field Mixing

In this paper, following a stream of investigation on supersymmetric gauge theories with cosmic string solutions, we contemplate the possibility of building up a D-and-F term cosmic string by means of a gauge-field mixing in connection with a U(1) x U(1)'-symmetry. The spontaneous break of both gauge symmetry and supersymmetry are thoroughly analysed and the fermion zero-modes are worked out. The role of the gauge-field mixing parameter is elucidated in connection with the string configuration that comes out. As an application of the model presented here, we propose the possibility that the supersimetric cosmic string yield production of fermionic charge carriers that may eject, at their late stages, particles that subsequently decay to produce cosmic rays of ultra-high energy. In our work, it turns out that massive supersymmetric fermionic partners may be produced for a susy breaking scale in the range 10^{11} to 10^{13} GeV, which is compatible with the phenomenology of a gravitino mass at the TeV scale. We also determine the range of the gauge-field mixing parameter, \alpha, in connection with the mass scales of the present model.Comment: 7 pages, no figures, ReVTex format, to appear in New Journal of Physic

Avaliação de genótipos de girassol para Vilhena, RO, na safrinha 2013.

O girassol (Helianthus annus) apresenta-se como cultura promissora para a diversificação da agricultura em todas as regiões do país, sobretudo como alternativa em sistemas de rotação ou em sucessão às culturas de soja e milho. Rondônia, apesar de todas as condições favoráveis não apresenta plantio de girassol em escala comercial. O ensaio foi realizado no campo experimental da Embrapa Rondônia em Vilhena, com o objetivo de avaliar diferentes genótipos de girassol e selecionar os mais adequados para o cultivo no cerrado de Rondônia. A semeadura foi realizada nos dias 6 e 7 de março de 2013, em delineamento de blocos casualizados, com três repetições; a parcela foi composta por 4 linhas de 5 m de comprimento, espaçadas em 0,90 m e parcela útil constituída por 2 linhas centrais de 4 m. As variáveis avaliadas foram dias para floração inicial, altura de planta, número de dias para maturação fisiológica, tamanho do capítulo e produtividade média de grãos (corrigida para 13% de umidade). O ensaio foi composto por oito genótipos: 12P3H1, 12P3H2, 12P3H3, 12P3H4, 12P3H5, 12P3H6 e as testemunhas: M734(T) e SYN039A(T). Os resultados foram analisados com software GENES, por meio de análise de variância e aplicação de teste Tuckey (P<0,01). Todas as variáveis apresentaram diferença significativa pelo teste F, exceto tamanho de capítulo. A média para início de florescimento foi de 57 dias após a semeadura. A altura média de plantas foi de 168 cm (variando entre 156 cm a 194 cm). A maturação fisiológica foi atingida, em média, aos 83 dias após a semeadura. A produtividade média foi de 1.682 kg.ha-1 , sendo o genótipo 12P3H3 o mais produtivo com 2.261 kg.ha-1 . Os resultados obtidos serão utilizados em análise com resultados de outros anos e localidades para indicar os melhores genótipos para cultivo na região

Magneto-Seebeck microscopy of domain switching in collinear antiferromagnet CuMnAs

Antiferromagnets offer spintronic device characteristics unparalleled in ferromagnets owing to their lack of stray fields, THz spin dynamics, and rich materials landscape. Microscopic imaging of antiferromagnetic domains is one of the key prerequisites for understanding physical principles of the device operation. However, adapting common magnetometry techniques to the dipolar-field-free antiferromagnets has been a major challenge. Here we demonstrate in a collinear antiferromagnet a thermoelectric detection method by combining the magneto-Seebeck effect with local heat gradients generated by scanning far-field or near-field techniques. In a 20-nm epilayer of uniaxial CuMnAs we observe reversible 180∘ switching of the Néel vector via domain wall displacement, controlled by the polarity of the current pulses. We also image polarity-dependent 90∘ switching of the Néel vector in a thicker biaxial film, and domain shattering induced at higher pulse amplitudes. The antiferromagnetic domain maps obtained by our laboratory technique are compared to measurements by the established synchrotron-based technique of x-ray photoemission electron microscopy using x-ray magnetic linear dichroism

Fungal endophytes of Panicum maximum and Pennisetum purpureum: isolation, identification, and determination of antifungal potential.

This study aimed to isolate and identify endophytic fungi from the forage grass P. maximum and evaluate their ability to inhibit the growth of plant pathogenic fungi. One sample from P. purpureum grass was also included. Surface disinfected stem fragments were used for endophytic fungal isolation. One hundred and twenty-six endophytic fungi were isolated, of which 118 were from P. maximum and eight from P. purpureum. Morphological characteristics and internal transcribed spacer (ITS) and 18S (NS) sequence comparisons identified most isolated endophytic fungi as belonging to the phylum Ascomycota, with Sarocladium being the dominant genus. The isolates were subjected to in vitro antagonism tests against pathogenic fungi, and 31 endophytic fungi inhibited the growth of Bipolaris maydis, Penicillium expansum, and Sclerotinia minor. The results expand our knowledge of the diversity of endophytes associated with tropical grasses and suggest that they may represent new sources of antifungal metabolites for biocontrol and biotechnological purposes

The effects of dictatorship on health: the case of Turkmenistan

BACKGROUND: There is a health crisis in Turkmenistan similar to, but more severe than, in other Central Asian countries. This paper asks whether the health crisis in Turkmenistan is attributable to the consequences of the dictatorship under president Niyazov, who died in 2006. METHODS: The basis for this paper was a series of semi-structured in-depth interviews with key informants complemented by an iterative search of internet sites, initially published as a report in April 2005, and subsequently updated with feedback on the report as well as a comprehensive search of secondary information sources and databases. RESULTS: This paper describes in depth three areas in which the dictatorship in Turkmenistan had a negative impact on population health: the regime's policy of secrecy and denial, which sees the "solution" to health care problems in concealment rather than prevention; its complicity in the trafficking of drugs from Afghanistan; and the neglect of its health care system. CONCLUSION: The paper concludes that dictatorship has contributed to the health crisis facing Turkmenistan. One of the first tests of the new regime will be whether it can address this crisis

Isolamento e potencial uso de bactérias do gênero Bacillus na promoção de crescimento de plantas em condições de déficit hídrico

O microbioma do solo é constituído por diferentes espécies de microrganismos, incluindo grupos capazes de promover o crescimento vegetal por meio da produção de fitormônios, proteínas e moléculas quelantes, solubilização de fosfato e potássio, fixação de nitrogênio, controle de alguns fitopatógenos e aumento da tolerância a estresses abióticos, como a seca. Dessa forma, o presente estudo objetivou isolar e selecionar bactérias tolerantes ao estresse hídrico e caracterizá-las indiretamente quanto à potencial capacidade de promoção de crescimento de plantas in vitro. Os microrganismos foram isolados de amostras de solos coletadas em diferentes municípios do Estado do Ceará em regiões da Caatinga. Os isolados bacterianos foram selecionados em meio de cultura enriquecido com diferentes concentrações de sorbitol, visando simular condições de restrição hídrica, avaliados quanto a características macromorfológicas e identificados molecularmente pelo sequenciamento do gene 16S rRNA. Um total de 414 cepas foi isolado do solo, das quais 28 foram capazes de crescer em meio de cultura contendo sorbitol nas concentrações de 520 e/ou 780 g L-1. As bactérias avaliadas apresentaram, em sua maioria, colônia pequena, de forma circular, elevação achatada, bordas lisas, opaca, na cor creme e com aspecto viscoso e foram identificadas como pertencentes ao gênero Bacillus, mostrando-se eficientes na produção de exopolissacarídeos e sideróforos. Além disso, 64% das cepas apresentaram capacidade de fixação de nitrogênio e 35% foram fortes produtoras de biofilme. Os diferentes isolados do gênero Bacillus são microrganismos promissores para a utilização na promoção do crescimento de plantas em condições de estresse hídrico.bitstream/item/205080/1/bol-192.pd

Wrinkling Labyrinth Patterns on Elastomeric Janus Particles

We describe a novel, low-cost and low-tech method for the fabrication of elastomeric Janus particles with diameters ranging from micrometers to millimeters. This consists of UV-irradiating soft urethane/urea elastomer spheres, which are then extracted in toluene and dried. The spheres are thus composed of a single material: no coating or film deposition steps are required. Furthermore, the whole procedure is carried out at ambient temperature and pressure. Long, labyrinthine corrugations ("wrinkles") appear on the irradiated portions of the particles' surfaces, the spatial periodicity of which can be controlled by varying the sizes of particles. The asymmetric morphology of the resulting Janus particles has been confirmed by scanning electron microscopy, atomic force microscopy, and optical microscopy. We have also established that the spheres behave elastically by performing bouncing tests with dried and swollen spheres. Results can be interpreted by assuming that each sphere consists of a thin, stiff surface layer ("skin") lying atop a thicker, softer substrate ("bulk"). The skin's higher stiffness is hypothesized to result from the more extensive cross-linking of the polymer chains located near the surface by the UV radiation. Textures then arise from competition between the effects of bending the skin and compressing the bulk, as the solvent evaporates and the sphere shrinks