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Rodriguez-Del-Bosque L.A.,Instituto Nacional de Investigaciones Nucleares
Southwestern Entomologist | Year: 2013

A laboratory study was used to compare the food consumption and survival of Oncideres pustulata LeConte adults that fed on huisache, Acacia farnesiana (L.) Willd., leucaena, Leucaena leucocephala (Lam.) de Wit, or both host plants. Longevity and food consumption differed significantly only among food plants, and no significant two-or three-way interactions were found. Longevity of O. pustulata was significantly greater on leucaena (77.6 days) than huisache (35.4 days). However, adults fed both host plants survived longer (90.3 days) than those that fed on either host plant alone. Total food consumption was more than two-fold greater in leucaena alone and leucaena + huisache than in huisache alone. However, daily consumption did not differ significantly among food regimes. When both huisache and leucaena were provided simultaneously, leucaena comprised an average of 67% of the total food consumed. Adult size was positively associated with average daily consumption, but not with longevity. Greater survival of O. pustulata on leucaena was attributed to better nutritional value and greater energy content compared to huisache. The greater longevity of O. pustulata fed on both leucaena and huisache probably reflects complementarity among amino acids and minerals contained in each host plant.

Yahia E.M.,Autonomous University of Queretaro | Mondragon-Jacobo C.,Instituto Nacional de Investigaciones Nucleares
Food Research International | Year: 2011

Cactus pear fruit (Opuntia) are harvested from various species of the genus Opuntia of the cactus family (Cactaceae), and are produced and consumed in several countries. We have characterized the nutritional content and antioxidant capacity (AC) of the fruit of ten cultivars/lines of distinct pulp colors. 'Camuesa' had the highest betalains, total carotenoids, ß-carotene, ascorbic acid, and was one of the highest in total phenolic compounds, but its AC did not demonstrate outstanding differences with some other cultivars/lines that were not as rich in these compounds. 'Roja Pelota' had high AC when measured with the DPPH assay, but had low total carotenoids, ß-carotene and total phenolic content. 'Reyna' had slightly low AC as measured by the FRAP assay, practically no betalains, and low vitamin C, tocopherols, ß-carotene, and total phenolic content. © 2011 Elsevier Ltd.

Aguilera E.F.,Instituto Nacional de Investigaciones Nucleares | Kolata J.J.,University of Notre Dame
Physical Review C - Nuclear Physics | Year: 2012

Recent experimental results for the fusion of the proton-halo system 8B+58Ni are discussed. A strong enhancement is observed both below and above the barrier. This is qualitatively different from the usual sub-barrier enhancement observed for many heavy-ion systems. Arguments are given that relate the enhancement to a static halo effect directly associated to the extended size of the proton-halo state. A simple single-barrier model is proposed which describes the fusion cross sections in terms of a maximum angular momentum for fusion, L f. It is shown that a linear energy dependence for L f gives a surprisingly good description of the experimental fusion excitation function not only for 8B+58Ni but also for the neutron-halo systems 6He+ (209Bi,64Zn). The model is also applied to several weakly bound systems. © 2012 American Physical Society.

Cabral-Prieto A.,Instituto Nacional de Investigaciones Nucleares
Hyperfine Interactions | Year: 2014

Simulated and experimental broadened Mössbauer spectra are analyzed using several distribution functions. The resolution Hesse and Rübartsch data are reproduced in order to analyze the origin of the oscillations appearing in the recovered distribution function. The lined triangular distribution is used and some of its properties are described. The no implicit nth-nomial distribution function P(x)=(aCos (πx) + bSin (πx))n is introduced, complementing the Window and Hesse and Rübartasch no implicit distribution functions. This new no implicit distribution function gives similar results of those of Window's method. In addition, the Window method has also been modified by inserting a smoothing factor λC. For 0<λC < 1 a hyperfine distribution with low resolution may be obtained; for λC > 1, the opposite is obtained. The Levenberg-Marquardt algorithm is used to solve the involved Fredholm integral equation rather than the typical second order regularized algorithm. From the extracted hyperfine field distribution functions of the Mössbauer spectra of the amorphous and crystallized Fe70Cr2Si5B16 magnetic alloy the short range atomic order for the amorphous state of this alloy can be inferred. © 2013 Springer Science+Business Media Dordrecht.

Aviles A.,National Autonomous University of Mexico | Cervantes-Cota J.L.,Instituto Nacional de Investigaciones Nucleares
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

We study some properties of the dark degeneracy, which is the fact that what we measure in gravitational experiments is the energy-momentum tensor of the total dark sector, and any split into components (as in dark matter and dark energy) is arbitrary. In fact, just one dark fluid is necessary to obtain exactly the same cosmological and astrophysical phenomenology as the ΛCDM model. We work explicitly the first-order perturbation theory and show that beyond the linear order the dark degeneracy is preserved under some general assumptions. Then we construct the dark fluid from a collection of interacting fluids. Finally, we try to break the degeneracy with a general class of couplings to baryonic matter. Nonetheless, we show that these interactions can also be understood in the context of the ΛCDM model as between dark matter and baryons. For this last investigation we choose two independent parametrizations for the interactions, one inspired by electromagnetism and the other by chameleon theories. Then, we constrain them with a joint analysis of CMB and supernovae observational data. © 2011 American Physical Society.

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