1,239 research outputs found
Composición química-funcional de aceites de Terminalia catappa de diferentes variedades
This study aimed to extract and physical-chemically characterize Terminalia catappa L. kernel oil from purple (CR) and yellow (CA) varieties. Physical-chemical parameters, composition of fatty acids, nutritional quality indices, bioactive compounds and antioxidant capacity of both oil varieties were evaluated according to the literature. Both oils presented low levels of acidity and peroxides, besides the predominance of unsaturated fatty acids, ~63% of oleic and ~26% of linoleic acids, which influenced its nutritional indices. The CR oil variety exhibited a higher content in anthocyanin (18.3 ± 1.5 mg·100 g-1), ascorbic acid (68.4 ± 2.02 mg·100 g-1) and total polyphenol contents (152.3 ± 2.4 mg GAE·g-1), and a good antioxidant activity (38.6 ± 2.2 μg TE·g-1) determined by TEAC assay, when compared to the CA oil (p < 0.05). Therefore, the results confirm the importance of T. catappa as a lipid source for human consumption to be used in the development of food products.El objetivo de este estudio fue extraer y caracterizar físico-químicamente aceite de semilla de Terminalia catappa de las variedades violeta (CR) y amarilla (CA). Se evaluaron parámetros fisicoquímicos, composición de ácidos grasos, índices de calidad nutricional, compuestos bioactivos y capacidad antioxidante de ambas variedades de aceite de acuerdo con a la literatura. Como resultado, ambos aceites presentaron bajos niveles de acidez y peróxidos, y predominio de ácidos grasos insaturados, ~63% de ácido oleico y ~26% de ácido linoleico, lo cual influyó en su perfil nutricional. La variedad de aceite CR presentó un mayor contenido de antocianina (18,3 ± 1,5 mg·100 g-1), ácido ascórbico (68,4 ± 2,02 mg·100 g-1) y contenido total de polifenoles (152,3 ± 2,4 mg GAE·g-1), y una alta actividad antioxidante (38,6 ± 2,2 μg TE·g-1) determinado por ensayo TEAC, en comparación con el aceite CA (p<0.05). En conclusión, los resultados presentados refuerzan la importancia de T. catappa como fuente de lípidos para la ingesta humana y para su uso en el desarrollo de productos alimenticios
From Fundamental Strings to Small Black Holes
We give evidence in favour of a string/black hole transition in the case of
BPS fundamental string states of the Heterotic string. Our analysis goes beyond
the counting of degrees of freedom and considers the evolution of dynamical
quantities in the process. As the coupling increases, the string states
decrease their size up to the string scale when a small black hole is formed.
We compute the absorption cross section for several fields in both the black
hole and the perturbative string phases. At zero frequency, these cross
sections can be seen as order parameters for the transition. In particular, for
the scalars fixed at the horizon the cross section evolves to zero when the
black hole is formed.Comment: 36 pages, 4 figures, argument about minimally coupled scalar
absorption cross section clarifie
Bianchi type II models in the presence of perfect fluid and anisotropic dark energy
Spatially homogeneous but totally anisotropic and non-flat Bianchi type II
cosmological model has been studied in general relativity in the presence of
two minimally interacting fluids; a perfect fluid as the matter fluid and a
hypothetical anisotropic fluid as the dark energy fluid. The Einstein's field
equations have been solved by applying two kinematical ans\"{a}tze: we have
assumed the variation law for the mean Hubble parameter that yields a constant
value of deceleration parameter, and one of the components of the shear tensor
has been considered proportional to the mean Hubble parameter. We have
particularly dwelled on the accelerating models with non-divergent expansion
anisotropy as the Universe evolves. Yielding anisotropic pressure, the fluid we
consider in the context of dark energy, can produce results that can be
produced in the presence of isotropic fluid in accordance with the \Lambda CDM
cosmology. However, the derived model gives additional opportunities by being
able to allow kinematics that cannot be produced in the presence of fluids that
yield only isotropic pressure. We have obtained well behaving cases where the
anisotropy of the expansion and the anisotropy of the fluid converge to finite
values (include zero) in the late Universe. We have also showed that although
the metric we consider is totally anisotropic, the anisotropy of the dark
energy is constrained to be axially symmetric, as long as the overall energy
momentum tensor possesses zero shear stress.Comment: 15 pages; 5 figures; matches the version published in The European
Physical Journal Plu
Surtos interespecíficos de dermatomicoses por Microsporum canis e Microsporum gypseum
Dermatomycosis in domestic animals are important zoonosis in view of the fact that they maintain close contact with human beings. Seven ringworm outbreaks are here described, one of M. gypseum involving a cat and a women and the remainder of M. canis involving 20 human beings (adults, young people and children), 5 dogs, 16 cats and a gibbon-monkey (Hylobates lar).As dermatomicoses dos animais domésticos constituem zoonoses importantes, urna vez que estes mantêm estreito contato com a espécie humana, dada a alta infectividade observada nesses processos. Relata-se a ocorrência de sete surtos de dermatomicoses, um por M. gypseum envolvendo um gato e um indivíduo do sexo feminino e os outros por M. canis envolvendo 20 indivíduos da espécie humana (adultos, jovens e crianças de ambos os sexos), 5 cães, 16 gatos e um macaco gibão (Hylobates lar)
Redox homeostasis in photosynthetic organisms: Novel and established thiol-based molecular mechanisms
Redox homeostasis consists of an intricate network in which reactive molecular species (RMS), redox modifications and redox proteins act in concert to allow both physiological responses and adaptation to stress conditions. This review highlights established and novel thiol-based regulatory pathways underlying the functional facets and significance of redox biology in photosynthetic organisms. This cannot be all-encompassing, but is intended to provide a comprehensive overview on the structural/molecular mechanisms governing the most relevant thiol switching modifications with emphasis on the large genetic and functional diversity of redox controllers (i.e. redoxins). We also summarize the different proteomic-based approaches aimed at investigating the dynamics of redox modifications and the recent evidence that extends the possibility to monitor the cellular redox state in vivo. Lastly, the physiological relevance of redox transitions is discussed based on reverse genetic studies confirming the importance of redox homeostasis in plant growth, development, and stress responses
Kinetic study of time-dependent fixation of UVI on biochar
Biochar, a by-product from the production of biofuel and syngas by gasification, was tested as a material for adsorption and fixation of UVI from aqueous solutions. A batch experiment was conducted to study the factors that influence the adsorption and time-dependent fixation on biochar at 20oC, including pH, initial concentration of UVI and contact time. Uranium (UVI) adsorption was highly dependent on pH but adsorption on biochar was high over a wide range of pH values, from 4.5 to 9.0, and adsorption strength was time-dependent over several days. The experimental data for pH > 7 were most effectively modelled using a Freundlich adsorption isotherm coupled to a reversible first order kinetic equation to describe the time-dependent fixation of UVI within the biochar structure. Desorption experiments showed that UVI was only sparingly desorbable from the biochar with time and isotopic dilution with 233UVI confirmed the low, or time-dependent, lability of adsorbed 238UVI. Below pH 7 the adsorption isotherm trend suggested precipitation, rather than true adsorption, may occur. However, across all pH values (4.5–9) measured saturation indices suggested precipitation was possible: autunite below pH 6.5 and either swartzite, liebigite or bayleyite above pH 6.5
Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
We review HB stars in a broad astrophysical context, including both variable
and non-variable stars. A reassessment of the Oosterhoff dichotomy is
presented, which provides unprecedented detail regarding its origin and
systematics. We show that the Oosterhoff dichotomy and the distribution of
globular clusters (GCs) in the HB morphology-metallicity plane both exclude,
with high statistical significance, the possibility that the Galactic halo may
have formed from the accretion of dwarf galaxies resembling present-day Milky
Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the
second-parameter problem is presented. A technique is proposed to estimate the
HB types of extragalactic GCs on the basis of integrated far-UV photometry. The
relationship between the absolute V magnitude of the HB at the RR Lyrae level
and metallicity, as obtained on the basis of trigonometric parallax
measurements for the star RR Lyrae, is also revisited, giving a distance
modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are
studied. Finally, the conductive opacities used in evolutionary calculations of
low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and
Space Scienc
Cosmic Evolution in a Modified Brans-Dicke Theory
We consider Brans-Dicke theory with a self-interacting potential in Einstein
conformal frame. We introduce a class of solutions in which an accelerating
expansion is possible in a spatially flat universe for positive and large
values of the Brans-Dicke parameter consistent with local gravity experiments.
In this Einstein frame formulation, the theory appears as an interacting
quintessence model in which the interaction term is given by the conformal
transformation. In such an interacting model, we shall show that the solutions
lead simultaneously to a constant ratio of energy densities of matter and the
scalar field.Comment: 11 pages, 3 figures, To appear in Astrophysics and Space Scienc
Application of genomicsassisted breeding for generation of climate resilient crops: progress and prospects
CCAFS Climat
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