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3. Frequency Shifts of photons emitted from geodesics of nonlinear electromagnetic black holes

Author

López, L. A. and Olvera, J. C.

Subjects
General Relativity and Quantum Cosmology
Abstract

We analyzed the frequency shifts of photons emitted from massive particles that move in stable geodesics around black holes with non-linear electrodynamics. The motion of the photon is modified by an effective metric when the Einstein gravity is coupled with non-linear electrodynamics. The kinematic shifts for photons are modified by the magnetic and electric factors that make the difference between the linear and non-linear electrodynamics. As an illustration, we present the frequency shifts of the photons for black holes with non-linear electrodynamics, two magnetic black holes, and two electric black holes, the Bardeen and Bronnikov black holes for the magnetic charge and the Born-Infeld and Dymnikova black holes for electric charge. These frequency shifts are compared with their linear electromagnetic counterpart.

Published
2020

5. Scattering and absorption sections of nonlinear electromagnetic black holes

Author

Olvera, J. C. and López, L. A.

Subjects
General Relativity and Quantum Cosmology
Abstract

The expression of the impact parameter, in the analysis for classical and semiclassical scattering cross sections for black holes, is obtained with nonlinear electrodynamics (NLED) while the absorption section is studied with the sinc approximation in the eikonal limit considering NLED. As an illustration, we calculate the classical and semiclassical scattering as well as the absorption sections for three black holes under NLED, the regular magnetic Bardeen and Bronnikov black holes and the singular Euler-Heisenberg black hole. All are compared with the sections of their linear electromagnetic counterpart, the Reissner-Nordstrom (RN) black hole. The comparison shows how NLED affects the sections as well as the variation with respect to the Reissner-Nordstrom sections, in some cases these variations are small.

Published
2019

8. Pre- and post-clinical–radiological and surgical evaluation of patients with pituitary adenoma and metabolic syndrome.

Author

Flores-Rabasa, R., González-Almazán, J. A., Cortés-Contreras, A. P., Méndez-García, L. A., Velasco, F., Navarro-Olvera, J. L., Aguado-Carrillo, G., Benítez-Gasca, A., and Carrillo-Ruiz, J. D.

Subjects
ENDOCRINE diseases, PITUITARY tumors, MAGNETIC resonance imaging, METABOLIC syndrome, BENIGN tumors
Abstract

Background: Pituitary adenomas are benign tumors located in the anterior hypophysis. Its appearance is associated with the development of parameters related to metabolic syndrome; therefore, surgical treatment could reduce associated morbimortality. Methods: Pre- and post-surgical MRI, using the Hardy–Wilson and Knosp classification, and clinical data according to the American Association of Clinical Endocrinology (AACE) criteria for metabolic syndrome: all the patients were followed-up until 208.57 days were reviewed on 217 consecutive patients with pituitary surgery. Results: Seventy-four patients were included in this study. There was a significant reduction in tumor size in mm3 [average pre- and post-surgery respectively: 12,362 mm3 (±12,397); 3,910 mm3 (±7,160)], (p < 0.0001). This was confirmed by the Hardy–Wilson and Knosp classification, where most patients went from grade IV C (33.7%) to grade 0 (12.1%), IA (20.2%), IIB (21.36%), and IIC (16.2%); as well as from grade 4 (24.3%) to grade 0 (45.9%), respectively. After surgery, there were statistically significant reductions in total serum levels of glucose [average pre- and post-surgery, respectively: 116 mg/dL (±26.9); 90 mg/dL (±10.2)], (p < 0.001), triglycerides [average pre- and post-surgery, 240 mg/dL (±102); 171 mg/dL (±60.5)], (p = 0.001); and HDL-c [average pre- and post-surgery, respectively: 39 mg/dL (±11.8); 44.6 mg/dL (±8.4)], (p = 0.029). The other parameters remained unchanged. Conclusion: This is the first study to demonstrate the relationship between the presence of pituitary adenoma and significative changes in serum glucose, triglycerides and c-HDL related to metabolic syndrome. [ABSTRACT FROM AUTHOR]

Published
2024
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9. Prescription of lipid-lowering therapy, LDLc control, and risk of MACE in patients after ST-elevation myocardial infarction in Mexico

Author

Hernandez Pastrana, S, primary, Villalobos Pedroza, M, additional, Robles Ledesma, M, additional, Najera Rojas, N A, additional, Juarez Tolen, J, additional, Ordonez Olvera, J C, additional, Diaz Herrera, B A, additional, Gonzalez Macedo, E, additional, Sierra Gonzalez De Cossio, A, additional, Garcia Espinosa, J I, additional, Arias Mendoza, A, additional, and Araiza Garaygordobil, D, additional

Published
2024
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26. Oncologic patients with covid 19: A mexican endeavor

Author

Shveid-Gerson, Daniela, primary, Noguez-Ramos, Alejandro, additional, Villegas-Osorno, Diana A., additional, Camarín-Sánchez, Efraín I., additional, López-Zepeda, Lorena, additional, Camacho-Limas, Christian P., additional, Villalobos-Prieto, Alberto, additional, Serrano-Olvera, J. Alberto, additional, and Gerson-Cwilich, Raquel, additional

Published
2021
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31. Effect of transcranial magnetic stimulation as an enhancer of cognitive stimulation sessions on mild cognitive impairment: Preliminary results

Author

Arias García Na, Roque Roque Gy, Ricardo Garcell J, González Olvera J, Cañizares Gómez S, Espino Cortés M, Ortega Cruz F, López Hidalgo M, Ortíz Baron A, Trejo Cruz G, Hernández Montiel H, Reyes-López Jv, Calderón Moctezuma Ar, and Aguilar Fabré L

Subjects
medicine.medical_specialty, Cognitive stimulation, Cognitive Behavioral Therapy, business.industry, medicine.medical_treatment, Montreal Cognitive Assessment, Audiology, medicine.disease, Mental Status and Dementia Tests, behavioral disciplines and activities, Transcranial Magnetic Stimulation, Transcranial magnetic stimulation, Psychiatry and Mental health, Cognition, Normal cognition, mental disorders, Medicine, Dementia, Humans, Cognitive Dysfunction, business, Cognitive impairment, Biological Psychiatry
Abstract

Mild cognitive impairment (MCI) is a state between normal cognition and dementia. Currently, there is little evidence of repetitive Transcranial Magnetic Stimulation (rTMS) as an enhancing tool for Cognitive Stimulation (CS) on MCI. The importance of this study consists in its assessment of the enhancing effect of rTMS on CS in 22 MCI patients randomized and divided into two group: active (AG) and sham (SG). Diagnoses and assessments were determined during 30 sessions over a 10-week period by Montreal Cognitive Assessment (MoCA) and Neuropsi test. Results were statistically significant in the intergroup analysis with MoCA and intragroup only for AG.

Published
2020

43. Effects of rTMS at 5 Hz over lDLPFC on inhibitory control and craving in cocaine-dependent patients

Author

Morelos Santana, E., primary, Garza-Villarreal, E., additional, Alcalá-Lozano, R., additional, Torres-Marcial, N., additional, Villicaña-Muñoz, V., additional, Fernández-Lozano, S., additional, Dávaloz-Guzmán, A., additional, Martínez-García, B., additional, González-Cantú, H., additional, Reyes-Zamorano, E., additional, and González-Olvera, J., additional

Published
2019
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47. Clinical effectiveness of 5Hz Transcranial Magnetic Stimulation applied on Left Dorsolateral Prefrontal Cortex and Dorsomedial Prefrontal Cortex on Clinical Depressed Patients

Author

Trejo Cruz, G., primary, Reyes López, J., additional, Ricardo Garcell, J., additional, Rodríguez Valdés, R., additional, Alcauter Solórzano, S., additional, Rodríguez Méndez, A., additional, Camacho Calderón, N., additional, González Olvera, J., additional, Roque Roque, G., additional, Calderón Moctezuma, Á., additional, and Hernández Montiel, H., additional

Published
2019
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48. Optimización en la producción de metano a partir de aguas residuales usando algoritmos metaheuristicos

Author

Morales Rivera, Juan P., Gurubel Tún, Kelly J., León Becerril, Elizabeth, Real Olvera, J. del, Zúñiga Grajeda, V., Morales Rivera, Juan P., Gurubel Tún, Kelly J., León Becerril, Elizabeth, Real Olvera, J. del, and Zúñiga Grajeda, V.

Abstract

El presente trabajo aborda el estudio de la producción de metano a partir de aguas residuales de la industria de las carnes frías, donde se propone la modificación de un modelo matemático para describir la digestión anaerobia previamente publicado en la literatura. Al comparar los datos experimentales obtenidos con los calculados por el modelo propuesto se encontró un ajuste R2 = 0.767, esto para valores de producción de metano puntual en sesenta días. Por otro lado, se propone en este trabajo una modificación al modelo propuesto y se optimizaron cinco diferentes parámetros cinéticos, por medio del algoritmo de búsqueda metaheurístico Particle Swarm Optimization (optimización de enjambre de partículas). Al evaluar los resultados de la optimización se observó una mejora en el ajuste inicial del modelo a R2 = 0.927, permitiendo concluir que este tipo de algoritmos metaheurísticos pueden ser muy eficaces al ajustar los parámetros de modelos altamente no lineales y así describir con mayor precisión los sistemas de digestión anaerobia.

Published
2019

49. Engineering privacy by design : Lessons from the design and implementation of an identity wallet platform

Author

Veseli, Fatbardh, Olvera, J. S., Pulls, Tobias, Rannenberg, Kai, Veseli, Fatbardh, Olvera, J. S., Pulls, Tobias, and Rannenberg, Kai

Abstract

Applying PbD principles to the design of a system is challenging. We provided our experience and lessons learnt from applying the LINDDUN as a privacy assessment framework in the design of the architecture for a cloud-based identity wallet platform. In this effort, we identified a need to improve LINDDUN in a number of cases, for which we proposed and documented concrete enhancements. We transform LINDDUN from a linear to an iterative process that requires adaptation, introduce the concept of “Constraints” and add a new step in the mitigation of threats. Further, we consider the mitigation strategies of LINDDUN too narrow, and propose other, more practicable ones. Finally, we not only identify further PETs for mitigating privacy threats, but also acknowledge the fact that some threats cannot be effectively mitigated with PETs alone. Thus, we introduce additional mitigation mechanisms besides PETs, introducing especially development guidelines and organizational measures. We demonstrate our enhancements with concrete examples, which could serve also other engineering projects following the PbD paradigm.

Published
2019
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50. Inversion of surface parameters using fast learning neural networks

Author

Dawson, M. S, Olvera, J, Fung, A. K, and Manry, M. T

Subjects
Earth Resources And Remote Sensing
Abstract

A neural network approach to the inversion of surface scattering parameters is presented. Simulated data sets based on a surface scattering model are used so that the data may be viewed as taken from a completely known randomly rough surface. The fast learning (FL) neural network and a multilayer perceptron (MLP) trained with backpropagation learning (BP network) are tested on the simulated backscattering data. The RMS error of training the FL network is found to be less than one half the error of the BP network while requiring one to two orders of magnitude less CPU time. When applied to inversion of parameters from a statistically rough surface, the FL method is successful at recovering the surface permittivity, the surface correlation length, and the RMS surface height in less time and with less error than the BP network. Further applications of the FL neural network to the inversion of parameters from backscatter measurements of an inhomogeneous layer above a half space are shown.

Published
1992

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