656 research outputs found

    The Space of Differences of Convex Functions on [0, 1]

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    ∗Participant in Workshop in Linear Analysis and Probability, Texas A & M University, College Station, Texas, 2000. Research partially supported by the Edmund Landau Center for Research in Mathematical Analysis and related areas, sponsored by Minerva Foundation (Germany).The space K[0, 1] of differences of convex functions on the closed interval [0, 1] is investigated as a dual Banach space. It is proved that a continuous function f on [0, 1] belongs to K[0, 1

    Molecular, Enzymatic, and Cellular Characterization of Soluble Adenylyl Cyclase From Aquatic Animals.

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    The enzyme soluble adenylyl cyclase (sAC) is the most recently identified source of the messenger molecule cyclic adenosine monophosphate. sAC is evolutionarily conserved from cyanobacteria to human, is directly stimulated by [Formula: see text] ions, and can act as a sensor of environmental and metabolic CO2, pH, and [Formula: see text] levels. sAC genes tend to have multiple alternative promoters, undergo extensive alternative splicing, be translated into low mRNA levels, and the numerous sAC protein isoforms may be present in various subcellular localizations. In aquatic organisms, sAC has been shown to mediate various functions including intracellular pH regulation in coral, blood acid/base regulation in shark, heart beat rate in hagfish, and NaCl absorption in fish intestine. Furthermore, sAC is present in multiple other species and tissues, and sAC protein and enzymatic activity have been reported in the cytoplasm, the nucleus, and other subcellular compartments, suggesting even more diverse physiological roles. Although the methods and experimental tools used to study sAC are conventional, the complexity of sAC genes and proteins requires special considerations that are discussed in this chapter

    Investigation of cAMP microdomains as a path to novel cancer diagnostics

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    AbstractUnderstanding of cAMP signaling has greatly improved over the past decade. The advent of live cell imaging techniques and more specific pharmacologic modulators has led to an improved understanding of the intricacies by which cAMP is able to modulate such a wide variety of cellular pathways. It is now appreciated that cAMP is able to activate multiple effector proteins at distinct areas in the cell leading to the activation of very different downstream targets. The investigation of signaling proteins in cancer is a common route to the development of diagnostic tools, prognostic tools, and/or therapeutic targets, and in this review we highlight how investigation of cAMP signaling microdomains driven by the soluble adenylyl cyclase in different cancers has led to the development of a novel cancer biomarker. Antibodies directed against the soluble adenylyl cyclase (sAC) are highly specific markers for melanoma especially for lentigo maligna melanoma and are being described as “second generation” cancer diagnostics, which are diagnostics that determine the ‘state’ of a cell and not just identify the cell type. Due to the wide presence of cAMP signaling pathways in cancer, we predict that further investigation of both sAC and other cAMP microdomains will lead to additional cancer biomarkers. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease

    A Educação Física como meio de conscientizar a população de Encantadas, Ilha do Mel, quanto a sua realidade social

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    Orientador: Marcus Aurélio Taborda de OliveiraMonografia (licenciatura) - Universidade Federal do Paraná. Setor de Ciências Biológicas. Curso de Educação Físic

    Topological regluing of rational functions

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    Regluing is a topological operation that helps to construct topological models for rational functions on the boundaries of certain hyperbolic components. It also has a holomorphic interpretation, with the flavor of infinite dimensional Thurston--Teichm\"uller theory. We will discuss a topological theory of regluing, and trace a direction in which a holomorphic theory can develop.Comment: 38 page

    Factorization of operators through subspaces of L-1-spaces

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    [EN] We analyze domination properties and factorization of operators in Banach spaces through subspaces of L1-spaces. Using vector measure integration and extending classical arguments based on scalar integral bounds, we provide characterizations of operators factoring through subspaces of L1-spaces of finite measures. Some special cases involving positivity and compactness of the operators are considered.Research supported by MINECO/FEDER under projects MTM2014-53009-P (J.M Calabuig), MTM2014-54182-P (J. Rodriguez) and MTM2012-36740-C02-02 (E. A. Sanchez-Perez).Calabuig, JM.; Rodríguez, J.; Sánchez Pérez, EA. (2017). Factorization of operators through subspaces of L-1-spaces. Journal of the Australian Mathematical Society. 103(3):313-328. https://doi.org/10.1017/S1446788716000513S3133281033Lindenstrauss, J., & Tzafriri, L. (1979). Classical Banach Spaces II. doi:10.1007/978-3-662-35347-9Pisier, G. (1986). Factorization of Linear Operators and Geometry of Banach Spaces. CBMS Regional Conference Series in Mathematics. doi:10.1090/cbms/060Okada, S., Ricker, W. J., & Sánchez Pérez, E. A. (2008). Optimal Domain and Integral Extension of Operators. doi:10.1007/978-3-7643-8648-1Lacey, H. E. (1974). The Isometric Theory of Classical Banach Spaces. doi:10.1007/978-3-642-65762-7Fernández, A., Mayoral, F., Naranjo, F., Sáez, C., & Sánchez-Pérez, E. A. (2005). Vector measure Maurey–Rosenthal-type factorizations and ℓ-sums of L1-spaces. Journal of Functional Analysis, 220(2), 460-485. doi:10.1016/j.jfa.2004.06.010Juan, M. A., & Sánchez Pérez, E. A. (2013). Maurey-Rosenthal domination for abstract Banach lattices. Journal of Inequalities and Applications, 2013(1). doi:10.1186/1029-242x-2013-213Avilés, A., Cabello Sánchez, F., Castillo, J. M. F., González, M., & Moreno, Y. (2013). On separably injective Banach spaces. Advances in Mathematics, 234, 192-216. doi:10.1016/j.aim.2012.10.013Defant, A., & Sánchez Pérez, E. A. (2004). Maurey–Rosenthal factorization of positive operators and convexity. Journal of Mathematical Analysis and Applications, 297(2), 771-790. doi:10.1016/j.jmaa.2004.04.047DEFANT, A., & PÉREZ, E. A. S. (2009). Domination of operators on function spaces. Mathematical Proceedings of the Cambridge Philosophical Society, 146(1), 57-66. doi:10.1017/s0305004108001734Bartle, R. G., Dunford, N., & Schwartz, J. (1955). Weak Compactness and Vector Measures. Canadian Journal of Mathematics, 7, 289-305. doi:10.4153/cjm-1955-032-1Rosenthal, H. P. (1974). A Characterization of Banach Spaces Containing l1. Proceedings of the National Academy of Sciences, 71(6), 2411-2413. doi:10.1073/pnas.71.6.2411Diestel, J., Jarchow, H., & Tonge, A. (1995). Absolutely Summing Operators. doi:10.1017/cbo9780511526138Rueda, P., & Sánchez-Pérez, E. A. (2015). Compactness in spaces of p-integrable functions with respect to a vector measure. Topological Methods in Nonlinear Analysis, 45(2), 641. doi:10.12775/tmna.2015.030Rosenthal, H. P. (1973). On Subspaces of L p. The Annals of Mathematics, 97(2), 344. doi:10.2307/1970850Diestel, J., & Uhl, J. (1977). Vector Measures. Mathematical Surveys and Monographs. doi:10.1090/surv/015[16] M. Mastyło and E. A. Sánchez-Pérez , ‘Factorization of operators through Orlicz spaces’, Bull. Malays. Math. Sci. Soc. doi:10.1007/s40840-015-0158-5, to appear.Calabuig, J. M., Lajara, S., Rodríguez, J., & Sánchez-Pérez, E. A. (2014). Compactness in L1of a vector measure. Studia Mathematica, 225(3), 259-282. doi:10.4064/sm225-3-6Defant, A. (2001). Positivity, 5(2), 153-175. doi:10.1023/a:1011466509838Fabian, M., Habala, P., Hájek, P., Montesinos, V., & Zizler, V. (2011). Banach Space Theory. CMS Books in Mathematics. doi:10.1007/978-1-4419-7515-

    Glucose and GLP-1 Stimulate cAMP Production via Distinct Adenylyl Cyclases in INS-1E Insulinoma Cells

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    In β cells, both glucose and hormones, such as GLP-1, stimulate production of the second messenger cAMP, but glucose and GLP-1 elicit distinct cellular responses. We now show in INS-1E insulinoma cells that glucose and GLP-1 produce cAMP with distinct kinetics via different adenylyl cyclases. GLP-1 induces a rapid cAMP signal mediated by G protein–responsive transmembrane adenylyl cyclases (tmAC). In contrast, glucose elicits a delayed cAMP rise mediated by bicarbonate, calcium, and ATP-sensitive soluble adenylyl cyclase (sAC). This glucose-induced, sAC-dependent cAMP rise is dependent upon calcium influx and is responsible for the glucose-induced activation of the mitogen-activated protein kinase (ERK1/2) pathway. These results demonstrate that sAC-generated and tmAC-generated cAMP define distinct signaling cascades
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