2,423 research outputs found

    The interplay between obesity and cancer: a fly view

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    Accumulating epidemiological evidence indicates a strong clinical association between obesity and an increased risk of cancer. The global pandemic of obesity indicates a public health trend towards a substantial increase in cancer incidence and mortality. However, the mechanisms that link obesity to cancer remain incompletely understood. The fruit fly Drosophila melanogaster has been increasingly used to model an expanding spectrum of human diseases. Fly models provide a genetically simpler system that is ideal for use as a first step towards dissecting disease interactions. Recently, the combining of fly models of diet-induced obesity with models of cancer has provided a novel model system in which to study the biological mechanisms that underlie the connections between obesity and cancer. In this Review, I summarize recent advances, made using Drosophila, in our understanding of the interplay between diet, obesity, insulin resistance and cancer. I also discuss how the biological mechanisms and therapeutic targets that have been identified in fly studies could be utilized to develop preventative interventions and treatment strategies for obesityassociated cancers

    Similarity between nuclear rainbow and meteorological rainbow -- evidence for nuclear ripples

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    We present evidence for the nuclear ripples superimposed on the Airy structure of the nuclear rainbow, which is similar to the meteorological rainbow. The mechanism of the nuclear ripples is also similar to that of the meteorological rainbow, which is caused by the interference between the externally reflective waves and refractive waves. The nuclear ripple structure was confirmed by analyzing the elastic angular distribution in 16^{16}O+12^{12}C rainbow scattering at ELE_L=115.9 MeV using the coupled channels method by taking account of coupling to the excited states of 12^{12}C and 16^{16}O with a double folding model derived from a density-dependent effective nucleon-nucleon force with realistic wave functions for 12^{12}C and 16^{16}O. The coupling to the excited states plays the role of creating the external reflection.Comment: 6 pages, 6 figure

    Evidence for a secondary bow in Newton's zero-order nuclear rainbow

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    Rainbows are generally considered to be caused by static refraction and reflection. A primary and a secondary rainbow appear due to refraction and internal reflection in a raindrop as explained by Newton. The quantum nuclear rainbow, which is generated by refraction in the nucleus droplet, only has a "primary" rainbow. Here we show for the first time evidence for the existence of a secondary nuclear rainbow generated dynamically by coupling to an excited state without internal reflection. This has been demonstrated for experimental 16^{16}O+12^{12}C scattering using the coupled channel method with an extended double folding potential derived from microscopic realistic wave functions for 12^{12}C and 16^{16}O.Comment: 5 pages, 4 figure

    Emergence of a secondary rainbow and the dynamical polarization potential for <sup>16</sup>O on <sup>12</sup>C at 330 MeV

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    Background: It was shown recently that an anomaly in the elastic scattering of 16O on 12C at around 300 MeV is resolved by including within the scattering model the inelastic excitation of specific collective excitations of both nuclei, leading to a secondary rainbow. There is very little systematic knowledge concerning the contribution of collective excitations to the interaction between nuclei, particularly in the overlap region when neither interacting nuclei are light nuclei. Purpose: Our goals are to study the dynamic polarization potential (DPP) generated by channel coupling that has been experimentally validated for a case (16O on 12C at around 300 MeV) where scattering is sensitive to the nuclear potential over a wide radial range; to exhibit evidence of the nonlocality due to collective coupling; to validate, or otherwise invalidate, the representation of the DPP by uniform renormalizing folding models or global potentials. Methods: S-matrix to potential, SL → V (r), inversion yields local potentials that reproduce the elastic channel S matrix of coupled channel calculations. Subtracting the elastic channel uncoupled potential yields a local L-independent representation of the DPP. The dependence of the DPP on the nature of the coupled states and other parameters can be studied. Results: Local DPPs were found due to the excitation of 12C and the combined excitation of 16O and 12C. The radial forms were different for the two cases, but each were very different from a uniform renormalization of the potential. The full coupling led to a 10% increase in the volume integral of the real potential. Evidence for the nonlocality of the underlying formal DPP and for the effect of direct coupling between the collective states is presented. Conclusions: The local DPP generating the secondary rainbow has been identified. In general, DPPs have forms that depend on the nature of the specific excitations generating them, but, as in this case, they cannot be represented by a uniform renormalization of a global model or folding model potential. The method employed herein is a useful tool for further exploration of the contribution of collective excitations to internuclear potentials, concerning which there is still remarkably little general information

    α\alpha + 92^{92}Zr cluster structure in 96^{96}Mo

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    In the evaluation of the half-life of the neutrinoless double-β\beta decay (0νββ0\nu\beta\beta) of a doubly closed-subshell nucleus 96^{96}Zr, the structure of the nucleus 96^{96}Mo is essentially important. The α\alpha-clustering aspects of 96^{96}Mo are investigated for the first time. By studying the nuclear rainbows in α\alpha scattering from 92^{92}Zr at high energies and the characteristic structure of the excitation functions at the extreme backward angle at the low-energy region, the interaction potential between the α\alpha particle and the 92^{92}Zr nucleus is determined well in the double folding model. The validity of the double folding model was reinforced by studying α\alpha scattering from neighboring nuclei 90^{90}Zr, 91^{91}Zr, and 94^{94}Zr. The double-folding-model calculations reproduced well all the observed angular distributions over a wide range of incident energies and the characteristic excitation functions. By using the obtained potential the α\alpha +92^{92}Zr cluster structure of 96^{96}Mo is investigated in the spirit of a unified description of scattering and structure. The existence of the second-higher nodal band states with the α\alpha+ 92^{92}Zr cluster structure, in which two more nodes are excited in the relative motion compared with the ground band, is demonstrated. The calculation reproduces well the ground-band states of 96^{96}Mo in agreement with experiment. The experimental B(E2)B(E2) value of the transition in the ground band is also reproduced well. The effect of α\alpha clustering in 96^{96}Mo on the the half-life of the 0νββ0\nu\beta\beta double-β\beta decay of 96^{96}Zr is discussed.Comment: 11 pages, 9 figure
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