Luis Ludeña

Universidad Tecnologica del Peru, Engineering, Alumnus

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Address: Lima, Provincia de Lima, Peru

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Academy of Athens

Harvard University

Salvador J. Diaz-Cano

King's College London

Fernanda Franco

PUC-GO

Eduardo Corona Pérez

Universidad de Sevilla

Sue Dolan

University of Leeds

Antonio Lopez-beltran

Luis Valero de Bernabe

Universidad Complutense de Madrid

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Papers by Luis Ludeña

Patoloía PUBLICACION OFICIALDE LA SOCIEDADESPAÑOLADE ANATOMIAPATOLOGICA

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Plasma norepinephrine, myocardial damage and left ventricular systolic function in Chagas' heart disease

International Journal of Cardiology, 1995

The functional status of the sympathetic nervous system in Chagas' heart disease is still the sub... more The functional status of the sympathetic nervous system in Chagas' heart disease is still the subject of intense controversy. To determine the nature of the abnormalities of the sympathetic nervous system, we measured the plasma norepinephrine concentration of chagasic patients with varying degrees of myocardial damage. Thirty-six patients with positive serology for Chagas' disease were studied. Twenty patients were in Functional Class I (New York Heart Association), 10 were in Functional Class II and six were in Functional Classes III-IV. Cardiac catheterization was performed in 24 patients. The asymptomatic patients had a plasma norepinephrine concentration (121 f 37 pg/ml, mean f S.D.) not different from normal controls (103 f 59 pg/ml). The symptomatic patients, however, had a significantly elevated plasma norepinephrine concentration (665 f 354 pg/ml, P < 0.001). The baseline heart rate of the asymptomatic and symptomatic patients directly correlated with the plasma norepinephrine concentration (r = 0.69, P < 0.0001). The symptomatic patients had larger ventricular volumes, higher left ventricular end-diastolic pressures and lower ejection fractions than the asymptomatic patients and normal controls. The plasma norepinephrine concentration correlated linearly with the left ventricular end-diastolic volume (r = 0.77, P < O.OOOl), and non-linearly with the ejection fraction (r = -0.70, P < 0.0001) and the left ventricular end-diastolic pressure (r = 0.53, P < 0.007). These results indicate that, in Chagas' heart disease as in most other cardiac diseases, sympathetic nervous system activation is a late and compensatory phenomenon. In other words, sympathetic activation is very likely related to the progressive impairment of left ventricular function.

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A reliable index for the prognostic significance of blood pressure variability

Journal of Hypertension, 2005

Objectives This study presents a reliable index inspired by the total variability concept of real... more

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The weizsacker term in density functional theory

Chemical Physics Letters, 1981

A general expression for the first-order reduced density matrix suggested by its form in terms of... more

A density functional theory test study on the N2··· He dimer

Theoretical Chemistry Accounts, 2001

In the present contribution we report a study of the weakly bound van der Waals N2–He molecule i... more In the present contribution we report a study of the weakly bound van der Waals N2–He molecule in the framework of the supermolecule approach by means of the PWPW and mPW1PW exchange–correlation functionals, using density functional theory local-spin-optimized atom-centered basis sets complemented with bond functions optimized at the mPW1PW level of theory. Calculations show that the mPW1PW functional using bond functions gives a realistic representation of the interaction-energy potentials for this van der Waals dimer, comparable to reference Møller–Plesset perturbation theory calculations. In contrast, the PWPW functional is unable to describe the bonding properties of this system and all values of the bonding properties obtained at different geometries with this functional are considered out-of-scale compared with the rest of the calculations presented in this study.

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Work meeting for the project "Poverty, Trade Policy and Complementary Policies" (Closed meeting) ECLAC-AECID Cooperation Programme "Policies and Instruments for the Promotion of the Growth in Latin America and the Caribbean II

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ENDOTHELIAL DYSFUNCTION AND BLOOD PRESSURE VARIABILITY IN NORMOTENSIVE ADOLESCENTS: PP.6.244

Journal of Hypertension, 2010

The genetic regulation of blood pressure (BP) and endothelial function is likely to be polygenic.... more The genetic regulation of blood pressure (BP) and endothelial function is likely to be polygenic. Because there is considerable variability in basal BP among inbred mouse strains, the purpose of this study was to determine whether a similar variability in vascular function exists among 7 "normotensive" strains. We tested the hypothesis that compared with mice with higher BPs, mice with lower BPs would have greater aortic endothelial responses to acetylcholine (ACh). Mean BP ranged from 117 to 145 mm Hg among the 7 strains. The responses of aortic rings to ACh, sodium nitroprusside, and papaverine were assessed after submaximal precontraction with prostaglandin F 2␣ . The aortas from all strains relaxed in a concentration-dependent manner to sodium nitroprusside and papaverine, but responses to ACh were markedly impaired in the aortas, but not carotid arteries, from 129P3/J and 129X1/SvJ mice. Aortas from the other strains relaxed normally to ACh. Furthermore, the endothelium-dependent dilators ADP and A23187 caused similar relaxation in 129P3/J, 129X1/SvJ, and C57BL/6J mice. Although the data do not support the initial hypothesis, the impaired aortic response to ACh in the 129 strains is a novel finding and illustrates the potential impact that genetic background can have on vascular responsiveness. (Arterioscler Thromb Vasc Biol. 2002;22:42-48.)

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e-Science perspectives in Venezuela

Computing Research Repository, 2008

We describe the e

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Kinetic energy and ground-state electron densities as fingerprints of wavefunction entanglement in two-electron spin-compensated atomic models

Journal of Physics A-mathematical and General, 2006

We take as a starting point the ground-state electron density in two-electron model atoms in whic... more We take as a starting point the ground-state electron density in two-electron model atoms in which Coulomb confinement in the He atom is first replaced by harmonic restoring forces. Switching off electron-electron interactions, one readily constructs a third-order differential equation for the ground-state electron density, as in the recent work of March and Ludeña (2004 Phys. Lett. A 330 16). We then switch on two different model interactions, first in the so-called Hookean atom going back to Kestner and Sinanoglu (1962 Phys. Rev. 128 2687), in which e2/r12 is retained as in He, and secondly in the Moshinsky (1968 Am. J. Phys. 36 52) atom in which Kr212/2 is switched on. Some analyticity properties of the low-order linear homogeneous differential equations which result are next studied. He-like atomic ions are then treated in the limit of large atomic number Z. In this latter case, one identifies both the electron-nuclear cusp, or equivalently Kato's theorem, and the corresponding electron-electron cusp in the ground-state spatial wavefunction Ψ(r1, r2). A final comment concerns quantum information and entanglement in relation to the recent work of Amovilli and March (2004 Phys. Rev. A 69 054302).

Kinetic energy and ground-state electron densities as fingerprints of wavefunction entanglement in two-electron spin-compensated atomic models

Journal of Physics A-mathematical and General, 2006

ABSTRACT We take as a starting point the ground-state electron density in two-electron model atom... more ABSTRACT We take as a starting point the ground-state electron density in two-electron model atoms in which Coulomb confinement in the He atom is first replaced by harmonic restoring forces. Switching off electron–electron interactions, one readily constructs a third-order differential equation for the ground-state electron density, as in the recent work of March and Ludeña (2004 Phys. Lett. A 330 16). We then switch on two different model interactions, first in the so-called Hookean atom going back to Kestner and Sinanoglu (1962 Phys. Rev. 128 2687), in which e2/r12 is retained as in He, and secondly in the Moshinsky (1968 Am. J. Phys. 36 52) atom in which Kr212/2 is switched on. Some analyticity properties of the low-order linear homogeneous differential equations which result are next studied. He-like atomic ions are then treated in the limit of large atomic number Z. In this latter case, one identifies both the electron–nuclear cusp, or equivalently Kato&#39;s theorem, and the corresponding electron–electron cusp in the ground-state spatial wavefunction Ψ(r1, r2). A final comment concerns quantum information and entanglement in relation to the recent work of Amovilli and March (2004 Phys. Rev. A 69 054302).

e-Science initiatives in Venezuela

Computing Research Repository, 2007

Within the context of the nascent e-Science infrastructure in Venezuela, we describe several webb... more Within the context of the nascent e-Science infrastructure in Venezuela, we describe several webbased scientific applications developed at the Centro Nacional de Cálculo Científico Universidad de Los Andes (CECALCULA), Mérida, and at the Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas. The different strategies that have been followed for implementing quantum chemistry and atomic physics applications are presented. We also briefly discuss a damage portal based on dynamic, nonlinear, finite elements of lumped damage mechanics and a biomedical portal developed within the framework of the E-Infrastructure shared between Europe and Latin America (EELA) initiative for searching common sequences and inferring their functions in parasitic diseases such as leishmaniasis, chagas and malaria.

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The Maracaibo Aging Study: Population and Methodological Issues

Neuroepidemiology, 2002

The Maracaibo Aging Study is a longitudinal, population-based, one-step multidisciplinary study o... more The Maracaibo Aging Study is a longitudinal, population-based, one-step multidisciplinary study of agerelated diseases, with a particular focus on memoryrelated disorders, among subjects over 55 years living in a neighborhood of the city of Maracaibo, Venezuela. Three phases were scheduled for this study. First, a doorto-door survey was conducted in order to build a registry and to obtain general and sociodemographic characteristics. During the second phase, information regarding changes in the abilities of the subjects was collected. The third phase consisted of a full neuropsychiatric examination, cardiovascular evaluation, nutritional assessment, neuropsychological testing, routine laboratory tests and genetic analysis. 3,657 subjects were surveyed between January and August, 1998. There were more women than men, and the average number of years of formal education was low, particularly among women. The limitations and strengths of the study are discussed.

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