475 research outputs found
Operational methods in the study of Sobolev-Jacobi polynomials
No full textInspired by ideas from umbral calculus and based on the two types of integrals occurring in the defining equations for the gamma and the reciprocal gamma functions, respectively, we develop a multi-variate version of umbral calculus and of the so-called umbral image technique. Besides providing a class of new formulae for generalized hypergeometric functions and an implementation of series manipulations for computing lacunary generating functions, our main application of these techniques is the study of Sobolev-Jacobi polynomials. Motivated by applications to theoretical chemistry, we moreover present a deep link between generalized normal-ordering techniques introduced by Gurappa and Panigrahi, two-variable Hermite polynomials and our integral-based series transforms. Notably, we thus calculate all K-tuple L-shifted lacunary exponential generating functions for a certain family of Sobolev-Jacobi (SJ) polynomials explicitly
Potential Benefits of Phytochemicals for Abdominal Aortic Aneurysm
No full textBackground: Abdominal aortic aneurysms (AAAs) are a leading cause of death in older adults due to aortic rupture. There are currently no effective medical therapies for AAA, with surgery being the only acceptable treatment. There is frequently an extended period between AAA diagnosis and treatment by corrective surgery, during which an effective drug therapy could prevent or delay the need for AAA repair.
Objective: This review aimed to critically summarize prior research investigating the potential benefits of phytochemicals in preventing or treating AAA.
Methods: In vitro, in vivo, and human studies examining the effect of phytochemicals in AAA models and patients were critically summarised.
Results: Some preliminary data support the further investigation of curcumin, radix astragali, grape seed polyphenols, resveratrol, Ginkgo biloba extract (EGb 761), Ginsenoide Rb1, Dan Hong, Epigallocatechin-3-gallate, Baicalein, Fucoidan, Quercetin, and Salvianolic acid as potential treatments for AAA.
Conclusion: Experimental in vivo and in vitro studies suggest the potential benefits of a number of medicinal herbs and phytochemicals in preventing or reducing the progression of AAA. In order to assess whether these findings can be translated into proven treatments, adequately designed double-blind randomized clinical trials will be required
Bardeen-Cooper-Schrieffer interaction as an infinite-range Penson-Kolb pairing mechanism
No full textWe demonstrate that the well-known
Bardeen-Cooper-Schrieffer interaction, when considered in real space, is
equivalent to an infinite-range Penson-Kolb pairing mechanism coexisting with
an attractive Hubbard term. Driven by this discovery and aiming at exploring
the conduction properties, we investigate the dynamics of fermionic particles
confined in a ring-shaped lattice. We assume that fermions are simultaneously
influenced by the pairing interaction and by an Aharonov-Bohm electromagnetic
phase, which is incorporated into the model in a highly non-trivial manner.
Remarkably, the aforementioned model shows Richardson integrability for both
integer and half-integer values of the applied magnetic flux ,
thus permitting the exact solution of a genuine many-body problem. We discuss
the ground state properties of both two-particle and many-particle systems,
drawing comparisons with results from the attractive Hubbard model. Our
approach combines exact diagonalization, density matrix renormalization group
techniques, and numerical solution of the Richardson equations. This
comprehensive analysis allows us to study various key metrics, including the
system's conductivity as a function of the interaction strength. In this way,
the BCS-BEC transition is investigated in a continuous manner, thus permitting
to shed light on fundamental aspects of superconducting pairing. Our findings
can be experimentally tested in a condensed matter context or, with greater
level of control, using atomtronics platforms.Comment: 21 pages, 9 figures; Updated version enhanced with comprehensive new
appendices, minor changes and corrections of residual typo
Levy stable distributions via associated integral transform
No full textWe present a method of generation of exact and explicit forms of one-sided, heavy-tailed Levy stable probability distributions g(alpha)(x), 0 <= x < infinity, 0 < alpha < 1. We demonstrate that the knowledge of one such a distribution g a ( x) suffices to obtain exactly g(alpha)p ( x), p = 2, 3, .... Similarly, from known g(alpha)(x) and g(beta)(x), 0 < alpha, beta < 1, we obtain g(alpha beta)( x). The method is based on the construction of the integral operator, called Levy transform, which implements the above operations. For a rational, alpha = l/k with l < k, we reproduce in this manner many of the recently obtained exact results for g(l/k)(x). This approach can be also recast as an application of the Efros theorem for generalized Laplace convolutions. It relies solely on efficient definite integration. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4709443]Agence Nationale de la Recherche (Paris, France)Agence Nationale de la Recherche (Paris, France) [ANR-08-BLAN-0243-2]PAN/French National Center for Scientific Research (CNRS) [4339]PAN/French National Center for Scientific Research (CNRS)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Brasil) [2010/15698-5]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Brasi
Mutational landscape, clonal evolution patterns, and role of RAS mutations in relapsed acute lymphoblastic leukemia
No full textChemotherapy Foundation; R01 CA185486, NIH, National Institutes of Health; U10 CA98543, NIH, National Institutes of Health; U54 CA193313, NIH, National Institutes of Health; St. Baldrick's FoundationOshima, K., Khiabanian, H., Da Silva-Almeida, A.C., Tzoneva, G., Abate, F., Ambesi-Impiombato, A., Sanchez-Martin, M., Carpenter, Z., Penson, A., Perez-Garcia, A., Eckert, C., Nicolas, C., Balbin, M., Sulis, M.L., Kato, M., Koh, K., Paganin, M., Basso, G., Gastier-Foster, J.M., Devidas, M., Loh, M.L., Kirschner-Schwabe, R., Palomero, T., Rabadan, R., Ferrando, A.A
Distributive concerns when replacing a pay-as-you-go system with a fully funded system
No full textThe author uses a simulation model to quantify the impact on income distribution of having a neutral social security program that is fully funded replace a progressive social security program that redistributes income toward the poor but is financed by a pay-as-you-go method. He finds that if the original pay-as-you-go system is large enough to yield an income replacement rate of at least 40 percent for the middle class and 200 percent for the poor, then the proposed change helps the poor in the long run, so long as public debt does not increase by more than 40 percent of GDP during the transition. Such a reform allows an increase in the capital stock per worker, so in the long run the poor benefit more through higher real wages than they lose because progressive redistribution has ended. In the short run, however, a compensatory program is needed because the poor lose their subsidy before receiving the long-term benefit. In most cases, the 40 percent of GDP available from the increase in public debt is enough to finance a transfer program that compensates the poor in the"short"run (the first 50 years). The author concludes that concern about the welfare of the poor is unwarranted, in both the short and long runs, if the compensatory program is implemented.Environmental Economics&Policies,Economic Theory&Research,Safety Nets and Transfers,Services&Transfers to Poor,Rural Poverty Reduction
IMPACT OF LOCALIZED CUTBACKS IN AGRICULTURAL PRODUCTION ON A STATE ECONOMY
No full textThis study examines the effects that a cutback in production by Texas agricultural producers would have on the economic well-being of all producers and consumers in the stateÂ’s economy. To do this, a quadratic input-output model incorporating econometric estimates of final demand was developed for the Texas economy. The output of the agricultural production sectors was constrained to reflect the cutback in production. The results show that agricultural producers would be economically worse off than before only if the producers of raw agricultural products in Texas imported their input needs from other geographical areas.Community/Rural/Urban Development, Production Economics,
Evidence-based assessment of lipoprotein(a) as a risk biomarker for cardiovascular diseases – some answers and still many questions
No full textThe present article is aimed to outline the current state of knowledge regarding the effects of lipoprotein(a) (Lp(a)) on cardiovascular disease (CVD) risk by summarizing the recent results of studies, meta-analyses and systematic reviews. The literature supports the predictive value of Lp(a) on CVD outcomes, although the effect size is modest. Lp(a) would also appear to have an effect on cerebrovascular outcomes, with the effect appearing even smaller than that for CVD outcomes. Consideration of apolipoprotein apolipoprotein(a) (apo (a)) isoforms and LPA genetics in relation to the simple assessment of Lp(a) concentration may enhance improving clinical practice in vascular medicine. We also describe recent advances in Lp(a) research (including therapies) and highlight areas where further research is needed such as the measurement of Lp(a) and its involvement in additional pathophysiological processes
On the properties of Laplace transform originating from one-sided Lévy stable laws
No full textInternational audienceWe consider the conventional Laplace transform of f(x), denoted by with . For we furnish the closed form expressions for the inverse Laplace transforms and . In both cases they involve definite integration with kernels which are appropriately rescaled one-sided Lévy stable probability distribution functions , , . Since are exactly and explicitly known for rational α, i.e. for with , , our results extend the known and tabulated case of to any rational . We examine the integral kernels of this procedure as well as the resulting two kinds of Lévy integral transformations
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