Análise in silico para identificação de minissatélites para a cultura da mandioca (Manihot esculenta Crantz).

O melhoramento genético pode ser auxiliado por ferramentas moleculares tornando-o mais preciso, rápido e contornando problemas inerentes à seleção fenotípica. O uso de marcadores moleculares permite, entre outros, eliminar genótipos redundantes e quando associados a uma característica, selecionar genótipos que a expressam. Com o sequenciamento da mandioca (Manihot esculenta Crantz) (PROCHNIK et al., 2012) aliado ao uso de ferramentas da bioinformática é possível o desenvolvimento de novas ferramentas moleculares ainda limitadas para essa cultura. Sequências repetitivas de DNA são abundantes no genoma dos eucariotos presentes em regiões de heterocromatina com raros exemplos em regiões gênicas ou de regulação. Os minissatélites são sequências de 6 a 100 nucleotídeos cujo polimorfismo é baseado nas diferenças em número de sequências repetitivas. Atualmente com o sequenciamento de várias espécies de plantas, a exemplo da mandioca, é possível a mineração de sequências com repetições minissatélites, o desenho de iniciadores e sua utilização via PCR trazendo maior praticidade a técnica. Os minissatélites possuem vantagens similares aos microssatélites como seu caráter multialélico, codominância e alto polimorfismo, adicionado à possibilidade de revelação em gel de agarose. São amplamente utilizados em estudos do genoma humano na detecção de locus impermutáveis e não há relatos de uso na cultura da mandioca. Desta forma, o objetivo deste trabalho foi a identificação regiões minissatélites via mineração de dados no genoma de mandioca

Polimorfismo da técnica Target Region Amplification Polymorphism (TRAP) para estudos moleculares em mandioca (Manihot esculenta Crantz).

O uso de marcadores moleculares constitui-se em uma técnica rápida que elimina a interferência dos fatores ambientais inerentes aos marcadores morfo-agronômicos na caracterização da diversidade e na busca por genes de interesse em diversas espécies. A cultura da mandioca (Manihot esculenta Crantz) apesar de diversos trabalhos de caracterização molecular, ainda necessita de maiores informações sobre sua expressão gênica e marcadores associados. O marcador TRAP é uma técnica baseada em PCR, que utiliza informações de ESTs (Expressed Sequence Tags) para gerar marcadores polimórficos relacionados a genes candidatos (HU e VICK, 2003). Alguns marcadores moleculares foram desenvolvidos para mandioca a partir de ESTs, a exemplo de microssatélites (ZOU et al, 2011). No entanto, a técnica TRAP traz como vantagem, além da amplificação de genes candidatos, a capacidade de produzir perfil de amplificação com muitas bandas por gel, o que diminui o custo por informação de polimorfismo. Desta forma, o objetivo deste trabalho foi avaliar o potencial de detecção de polimorfismo em regiões gênicas na cultura da mandioca com uso de marcadores do tipo TRAP

Programmed buckling by controlled lateral swelling in a thin elastic sheet

Recent experiments have imposed controlled swelling patterns on thin polymer films, which subsequently buckle into three-dimensional shapes. We develop a solution to the design problem suggested by such systems, namely, if and how one can generate particular three-dimensional shapes from thin elastic sheets by mere imposition of a two-dimensional pattern of locally isotropic growth. Not every shape is possible. Several types of obstruction can arise, some of which depend on the sheet thickness. We provide some examples using the axisymmetric form of the problem, which is analytically tractable.Comment: 11 pages, 9 figure

On the differential geometry of curves in Minkowski space

We discuss some aspects of the differential geometry of curves in Minkowski space. We establish the Serret-Frenet equations in Minkowski space and use them to give a very simple proof of the fundamental theorem of curves in Minkowski space. We also state and prove two other theorems which represent Minkowskian versions of a very known theorem of the differential geometry of curves in tridimensional Euclidean space. We discuss the general solution for torsionless paths in Minkowki space. We then apply the four-dimensional Serret-Frenet equations to describe the motion of a charged test particle in a constant and uniform electromagnetic field and show how the curvature and the torsions of the four-dimensional path of the particle contain information on the electromagnetic field acting on the particle.Comment: 10 pages. Typeset using REVTE

Perturbation theory for plasmonic eigenvalues

We develop a perturbative approach for calculating, within the quasistatic approximation, the shift of surface resonances in response to a deformation of a dielectric volume. Our strategy is based on the conversion of the homogeneous system for the potential which determines the plasmonic eigenvalues into an inhomogeneous system for the potential's derivative with respect to the deformation strength, and on the exploitation of the corresponding compatibility condition. The resulting general expression for the first-order shift is verified for two explicitly solvable cases, and for a realistic example of a deformed nanosphere. It can be used for scanning the huge parameter space of possible shape fluctuations with only quite small computational effort

Anti-aging activity of Lobophora variegata ethanolic and methanolic extracts and their fractions

Conference Report XVI International Symposium on Marine Natural Products | XI European Conference on Marine Natural Products, 1-5 September 2019, Peniche, Portugal.Seaweed have promising applications within food, cosmetic and health industries, which led to an increased interest in studying these organisms [1]. In several coastal areas, thousands of tons of macroalgae are cast on beaches and shorelines and it would be very interesting if this biomass could be managed, allowing the extraction of added-value compounds. In this context, polar extracts (methanol and ethanol) of a macroalgal beach cast sample mainly composed of “Lobophora variegate” were prepared and the anti-aging and antioxidant activities were evaluated. The preliminary results showed interesting results, and thus these crude extracts were then fractionated sequentially by their solubility in dichloromethane, acetone and ethyl acetate, resulting in 4 semi-pure fractions each, which were also tested. Fractions A1.1.1 and A1.2.3 were very good tyrosinase inhibitors (IC₅₀ = 37.87 and 24.01 μg/mL, respectively) and fractions A1.1.2 and A1.2.2 presented very good inhibition of elastase (IC₅₀ = 44.76 and 20.86 μg/mL, respectively). However, none of the fractions was active against collagenase. These results show that further purifications of these fractions can lead to the isolation of bioactive added-value compounds.info:eu-repo/semantics/publishedVersio

Primary and secondary scintillation measurements in a xenon Gas Proportional Scintillation Counter

NEXT is a new experiment to search for neutrinoless double beta decay using a 100 kg radio-pure high-pressure gaseous xenon TPC. The detector requires excellent energy resolution, which can be achieved in a Xe TPC with electroluminescence readout. Hamamatsu R8520-06SEL photomultipliers are good candidates for the scintillation readout. The performance of this photomultiplier, used as VUV photosensor in a gas proportional scintillation counter, was investigated. Initial results for the detection of primary and secondary scintillation produced as a result of the interaction of 5.9 keV X-rays in gaseous xenon, at room temperature and at pressures up to 3 bar, are presented. An energy resolution of 8.0% was obtained for secondary scintillation produced by 5.9 keV X-rays. No significant variation of the primary scintillation was observed for different pressures (1, 2 and 3 bar) and for electric fields up to 0.8 V cm-1 torr-1 in the drift region, demonstrating negligible recombination luminescence. A primary scintillation yield of 81 \pm 7 photons was obtained for 5.9 keV X-rays, corresponding to a mean energy of 72 \pm 6 eV to produce a primary scintillation photon in xenon.Comment: 16 pages, 10 figures, accepted for publication in JINS

Aharonov-Bohm-like effect for light propagating in nematics with disclinations

Using a geometric approach for the propagation of light in anisotropic media, we investigate what effect the director field of disclinations may have on the polarization state of light. Parallel transport around the defect, of the spinor describing the polarization, indicates the acquisition of a topological phase, in analogy with the Aharonov-Bohm effect.Comment: 6 pages, to appear in Europhysics Letter

Uso da técnica TRAP (Target Region Amplification Polymorphism) para análises genéticas em mandioca.

O melhoramento genético integrado às técnicas da biotecnologia contribui principalmente para o aumento da produtividade das culturas comerciais, em sua adaptação aos variados ambientes e resistência a patógen

Soliton surfaces associated with symmetries of ODEs written in Lax representation

The main aim of this paper is to discuss recent results on the adaptation of the Fokas-Gel'fand procedure for constructing soliton surfaces in Lie algebras, which was originally derived for PDEs [Grundland, Post 2011], to the case of integrable ODEs admitting Lax representations. We give explicit forms of the \g-valued immersion functions based on conformal symmetries involving the spectral parameter, a gauge transformation of the wave function and generalized symmetries of the linear spectral problem. The procedure is applied to a symmetry reduction of the static $\phi^4$-field equations leading to the Jacobian elliptic equation. As examples, we obtain diverse types of surfaces for different choices of Jacobian elliptic functions for a range of values of parameters.Comment: 14 Pages, 2 figures Conference Proceedings for QST7 Pragu