69,150 research outputs found

    A relativistic one dimensional band model with position dependent mass

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    Producción CientíficaIn this note a one-dimensional band model is proposed based on a periodic Dirac comb having a periodic mass distribution m(x). The mass function is represented as a Hermitian, non-local separable operator. Two specific cases–a constant mass model and a sinusoidal mass model–are examined. The lowest electron and positron bands for the constant mass case are similar to those for the standard relativistic Kronig-Penney model, suggesting that non-locality has little influence. The results for the sinusoidal case are consistent with the expectation that at low wavenumber an electron “feels” it has an average constant mass, but at high wave number, the particle “sees” the periodic mass variation and the band is distorted.Ministerio de Economía, Industria y Competitividad (project MTM2014-57129-C2-1-P)Junta de Castilla y León (project VA057U16

    A note on the Moll-Arias de Reyna integral

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    ProducciĂłn CientĂ­ficaThe Moll-Arias de Reyna integral is generalized and several values are given.Ministerio de EconomĂ­a, Industria y Competitividad (project MTM2014-57129-C2-1-P)Junta de Castilla y LeĂłn (project VA057U16

    Green Documentary: Environmental Documentary in the 21st Century by Helen Hughes

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    David M. Lawrence reviews Green Documentary: Environmental Documentary in the 21st Century by Helen Hughes

    The Big Bang, Modern Cosmology and the Fate of the Universe: Impacts upon Culture

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    Cosmological discoveries over the past century have completely changed our picture of our place in the universe. New observations have a realistic chance of probing nature on heretofore unimaginable scales, and as a result are changing the nature of fundamental science. Perhaps no other domain of science has an equal capacity to completely change our perspective of the world in which we live.Comment: Invited Lecture, UNESCO/IAU Meeting: The Role of Astronomy in Society and Culture Jan 2009, to appear, IAU Proceedings, D. Valls-Gaubaud and A. Boksenberg, eds.. (Several typos removed in this version

    Tumor angiogenic switch determines sustained proliferative malignant transformation in tumorigenesis and overlaps with para-inflammatory phenomena

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    Contextual BCR-ABL tyrosine kinase over-activity determines in formulated fashion the emergence of proliferation and anti-apoptosis that arise largely as derived phenomena of otherwise homeostatic mechanisms of the c-ABL gene within hematopoietic stem cells and hemangioblasts in the bone marrow. The ability to suppress almost completely, both in terms of phenotype and cytogenetically, the myeloid cell line expansion by imatinib mesylate is indicative of a phenomenon that depends strictly on the transformed status of the cell of origin in the chronic myeloid leukemia process. It is with relevance to complex participation of the dynamics of the fused BCR- ABL protein product that contextual conditioning of the cells of origin of the gene translocation further motivates the dimensional expansion of the transformed myeloid cell clones to increasing proliferative rates, thus leading to blast crisis as eventual loss of differentiating potential.peer-reviewe

    The Charitable Foundation: Its Governance

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    A dual origin for Bcr-Abl gene translocation/fusion as dynamics of synergism of the hematopoietic stem cell and hemangioblast in chronic myeloid leukemia

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    Contextual BCR-ABL tyrosine kinase over-activity determines in formulated fashion the emergence of proliferation and anti-apoptosis that arise largely as derived phenomena of otherwise homeostatic mechanisms of the c-ABL gene within hematopoietic stem cells and hemangioblasts in the bone marrow. The ability to suppress almost completely, both in terms of phenotype and cytogenetically, the myeloid cell line expansion by imatinib mesylate is indicative of a phenomenon that depends strictly on the transformed status of the cell of origin in the chronic myeloid leukemia process. It is with relevance to complex participation of the dynamics of the fused BCR- ABL protein product that contextual conditioning of the cells of origin of the gene translocation further motivates the dimensional expansion of the transformed myeloid cell clones to increasing proliferative rates, thus leading to blast crisis as eventual loss of differentiating potential.peer-reviewe
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