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Search Results: 1 - 10 of 29112 matches for " Gregory Fernando; "
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La metafilosofía de los pragmatistas clásicos
Pappas,Gregory Fernando;
Discusiones Filosóficas , 2010,
Abstract: in this paper i argue that the metaphilosophy of pragmatists is the most important contribution of these philosophers to the history of philosophy and is also what distinguishes them from other philosophers. the classic american philosophers (peirce, james, and dewey) and the hispanic philosophers, ortega y gasset and risieri frondizi, proposed that philosophy must start from experience. after explaining what it means to take experience as the starting point, i examine the reasons that pragmatists philosophers have for holding the view that experience should be the starting point if philosophy is to be empirical and relevant.
Fast Adaptive Algorithms in the Non-Standard Form for Multidimensional Problems
Gregory Beylkin,Vani Cheruvu,Fernando Pérez
Mathematics , 2007,
Abstract: We present a fast, adaptive multiresolution algorithm for applying integral operators with a wide class of radially symmetric kernels in dimensions one, two and three. This algorithm is made efficient by the use of separated representations of the kernel. We discuss operators of the class $(-\Delta+\mu^{2}I)^{-\alpha}$, where $\mu\geq0$ and $0<\alpha<3/2$, and illustrate the algorithm for the Poisson and Schr\"{o}dinger equations in dimension three. The same algorithm may be used for all operators with radially symmetric kernels approximated as a weighted sum of Gaussians, making it applicable across multiple fields by reusing a single implementation. This fast algorithm provides controllable accuracy at a reasonable cost, comparable to that of the Fast Multipole Method (FMM). It differs from the FMM by the type of approximation used to represent kernels and has an advantage of being easily extendable to higher dimensions.
Pathogenesis of Endometriosis and Uterine Fibroids
Pasquapina Ciarmela,Hilary Critchley,Gregory M. Christman,Fernando M. Reis
Obstetrics and Gynecology International , 2013, DOI: 10.1155/2013/656571
Abstract:
Approximating a Wavefunction as an Unconstrained Sum of Slater Determinants
Gregory Beylkin,Martin J. Mohlenkamp,Fernando Pérez
Mathematics , 2007, DOI: 10.1063/1.2873123
Abstract: The wavefunction for the multiparticle Schr\"odinger equation is a function of many variables and satisfies an antisymmetry condition, so it is natural to approximate it as a sum of Slater determinants. Many current methods do so, but they impose additional structural constraints on the determinants, such as orthogonality between orbitals or an excitation pattern. We present a method without any such constraints, by which we hope to obtain much more efficient expansions, and insight into the inherent structure of the wavefunction. We use an integral formulation of the problem, a Green's function iteration, and a fitting procedure based on the computational paradigm of separated representations. The core procedure is the construction and solution of a matrix-integral system derived from antisymmetric inner products involving the potential operators. We show how to construct and solve this system with computational complexity competitive with current methods.
Unique Measure for the Time-Periodic Navier-Stokes on the Sphere Navier-Stokes on the Sphere  [PDF]
Gregory Varner
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.611160
Abstract:

This paper proves the existence and uniqueness of a time-invariant measure for the 2D Navier-Stokes equations on the sphere under a random kick-force and a time-periodic deterministic force. Several examples of deterministic force satisfying the necessary conditions for a unique invariant measure to exist are given. The support of the measure is examined and given explicitly for several cases.

The Scaling Constant D in Item Response Theory  [PDF]
Gregory Camilli
Open Journal of Statistics (OJS) , 2017, DOI: 10.4236/ojs.2017.75055
Abstract: In item response theory (IRT), the scaling constant D = 1.7 is used to scale a discrimination coefficient a estimated with the logistic model to the normal metric. Empirical verification is provided that Savalei’s[1] proposed a scaling constant of D = 1.749 based on Kullback-Leibler divergence appears to give the best empirical approximation. However, the understanding of this issue as one of the accuracy of the approximation is incorrect for two reasons. First, scaling does not affect the fit of the logistic model to the data. Second, the best scaling constant to the normal metric varies with item difficulty, and the constant D = 1.749 is best thought of as the average of scaling transformations across items. The reason why the traditional scaling with D = 1.7 is used is simply because it preserves historical interpretation of the metric of item discrimination parameters.
An Exploratory Survey of Sound Levels in New York City Restaurants and Bars  [PDF]
Gregory Scott
Open Journal of Social Sciences (JSS) , 2018, DOI: 10.4236/jss.2018.68005
Abstract: For several decades, there has been a significant need to better educate the public about noise pollution. A small number of small-scale studies have focused on the sound levels of restaurants and their impact on health and hearing. There have also been an increasing number of media articles stating that eating and drinking venues are getting increasingly loud making it more difficult for people to connect with others in conversation. This study reports on an exploratory large-scale noise survey of sound levels of 2376 restaurants and bars in New York City using a novel smart-phone application and categorized them based on how quiet or loud they were. The results suggest that: 1) A significant number of venues have high sound levels that are not conducive to conversation and may be endangering the health of patrons and employees, 2) that the reported sound levels by the venue managers on their online public business pages generally underestimated actual sound levels, and 3) the average sound levels in restaurants and bars are correlated by neighborhood and type of cuisine.
Transcription analysis of TIMP-1 and NM23-h1 genes in glioma cell invasion
Nasser, José Augusto;Falavigna, Asdrúbal;Ferraz, Fernando;Duigou, Gregory;Bruce, Jeffrey;
Arquivos de Neuro-Psiquiatria , 2006, DOI: 10.1590/S0004-282X2006000500014
Abstract: purpose: to evaluate using transcription analysis the presence and importance of two genes: nm23-h1 and timp-1 on control of tumor cell invasion in diffuse astrocytomas (who ii) and glioblastoma multiforme (who iv). method: northern blot analysis of nm23-h1 and timp-1 was performed. eight diffuse astrocytomas and 19 glioblastomas (who iv) were analyzed to determine if timp-1 and nm23-h1 were candidates to inhibition of tumor cell invasion quantitated rna levels. the samples were collected directly from operating room. total cellular rna was extracted from frozen tissue samples using guanidinium-isothiocyanate and cesium chloride gradients. total rna (10 mg per sample) from tumor tissue were size fractionated through 1% agarose-formaldehyde gel and transferred to nylon filters and then hybridized to 32p-labeled dna probes and placed for autoradiography. levels of specific rnas were determined by computer-assisted laser densitometry. blot filters were sequentially hybridized to nm23 and timp-1 probes in addition to gapdh, as a control. statistical analyses were carried out according to t-test for equality of means. results: nm23-h1 were detected in each sample, however it did not correlate with malignancy and invasiveness. on the other side timp-1 gene expression showed a clear correlation between low expression and invasiveness. conclusion: the data suggest that timp-1 is an inhibitor of high grade gliomas invasion. nm23-h1 was present in the entire gliomas sample, but it did not vary in diffuse astrocytomas and glioblastomas.
An evolutionary frame of work to study physiological adaptation to high altitudes
REZENDE,ENRICO L.; GOMES,FERNANDO R.; GHALAMBOR,CAMERON K.; RUSSELL,GREGORY A.; CHAPPELLl,MARK A.;
Revista chilena de historia natural , 2005, DOI: 10.4067/S0716-078X2005000200016
Abstract: how complex physiological systems evolve is one of the major questions in evolutionary physiology. for example, how traits interact at the physiological and genetic level, what are the roles of development and plasticity in darwinian evolution, and eventually how physiological traits will evolve, remains poorly understood. in this article we summarize the current frame of work evolutionary physiologists are employing to study the evolution of physiological adaptations, as well as the role of developmental and reversible phenotypic plasticity in this context. we also highlight representative examples of how the integration of evolutionary and developmental physiology, concomitantly with the mechanistic understanding of physiological systems, can provide a deeper insight on how endothermic vertebrates could cope with reduced ambient temperatures and oxygen availability characteristic of high altitude environments. in this context, high altitude offers a unique system to study the evolution of physiological traits, and we believe much can be gained by integrating theoretical and empirical knowledge from evolutionary biology, such as life-history theory or the comparative method, with the mechanistic understanding of physiological processes
An evolutionary frame of work to study physiological adaptation to high altitudes Un marco conceptual para estudiar adaptaciones fisiológicas a altas altitudes
ENRICO L. REZENDE,FERNANDO R. GOMES,CAMERON K. GHALAMBOR,GREGORY A. RUSSELL
Revista chilena de historia natural , 2005,
Abstract: How complex physiological systems evolve is one of the major questions in evolutionary physiology. For example, how traits interact at the physiological and genetic level, what are the roles of development and plasticity in Darwinian evolution, and eventually how physiological traits will evolve, remains poorly understood. In this article we summarize the current frame of work evolutionary physiologists are employing to study the evolution of physiological adaptations, as well as the role of developmental and reversible phenotypic plasticity in this context. We also highlight representative examples of how the integration of evolutionary and developmental physiology, concomitantly with the mechanistic understanding of physiological systems, can provide a deeper insight on how endothermic vertebrates could cope with reduced ambient temperatures and oxygen availability characteristic of high altitude environments. In this context, high altitude offers a unique system to study the evolution of physiological traits, and we believe much can be gained by integrating theoretical and empirical knowledge from evolutionary biology, such as life-history theory or the comparative method, with the mechanistic understanding of physiological processes Una de las preguntas más importantes en fisiología evolutiva es como evolucionan los sistemas fisiológicos complejos. Por ejemplo, actualmente sabemos poco sobre la interacción entre varios rasgos a niveles genéticos y fisiológicos, sobre el papel de la plasticidad fenotípica durante distintas etapas del desarrollo y madurez para la evolución fisiológica dentro de un linaje. En este trabajo explicamos el marco conceptual ocupado por fisiólogos evolutivos en la actualidad para estudiar adaptaciones fisiológicas a nivel evolutivo y el papel de la plasticidad dentro de la evolución Darviniana. Citamos ejemplos de como la integración de la fisiología evolutiva y del desarrollo nos permitió un mayor entendimiento de como vertebrados endotérmicos pueden "adaptarse" a altas altitudes. Los organismos de alta altitud ofrecen un excelente sistema para estudiar la evolución de rasgos fisiológicos, y hay mucho por aprender en ese contexto al integrarse el conocimiento teórico y empírico de la biología evolutiva, tales como teoría de historia de vida o el método comparativo, con el conocimiento mecanicista de los procesos fisiológicos
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