Search

Your search keyword '"Velez, Carlos"' showing total 387 results
Start Over Author "Velez, Carlos" Search Limiters Academic (Peer-Reviewed) Journals
387 results on '"Velez, Carlos"'

1. Convolutional neural networks applied to modification of images

Author

Aguirre-Velez, Carlos I., Arciniega-Nevarez, Jose Antonio, and Dolores-Cuenca, Eric

Subjects
Computer Science - Computer Vision and Pattern Recognition, A.1, G.m
Abstract

The reader will learn how digital images are edited using linear algebra and calculus. Starting from the concept of filter towards machine learning techniques such as convolutional neural networks., Comment: 23 pages

Published
2024
Full Text
View/download PDF

4. Post exposure prophylaxis for HIV in the sexual exposure scenario (PEPSE) : development of a novel nanoformulation

Author

Sanders Velez, Carlos

Subjects
RM Therapeutics. Pharmacology, RS Pharmacy and materia medica
Abstract

Since the year 2012, 2 million newly diagnosed cases of human immunodeficiency virus (HIV) have been found every year. Prevention schemes based on condoms, and other pharmacological interventions such as post exposure prophylaxis in a sexual exposure scenario (PEPSE) have had positive impact in the pandemic. Under current PEPSE guidelines due to risk to benefit ratios, only high-risk unprotected sexual events (>1/1000) are prescribed antiviral prophylaxis. Such a situation leaves a population unprotected, whose size is unknown, that is in a low to moderate risk of HIV acquisition. To assess the size and views of a population that is currently unprotected by current prevention schemes, two online survey studies were set up in Thailand and the UK (Chapter 2). Both questionnaires were designed to probe for unplanned low to moderate risk of sexual exposure to HIV. Both data sets were analysed through demographic statistics and logistic regression to assess for unsafe intercourse. The results suggest that the proportion of the population reporting unplanned unsafe sexual intercourse events is as high as 29.1% in the UK study and 15.8% in the study in Thailand. Such a high proportion of sexually active population presents a target for further alternative prevention schemes and a research priority. One such alternative prevention scheme would be a localised (anal or vaginal delivery) nanoparticle drug delivery system, with high drug content, targeting local lymphatic nodes (Chapter 3). Dolutegravir (DTG) was chosen as the model antiretroviral agent due to its favourable side effect profile, high genetic barrier and high antiviral potency. However, the physiochemical properties of DTG such as its hydrophilicity are a challenge for the entrapment of DTG under traditional nanoformualtions. A DTG prodrug, dolutegravir myristate (MDTG) was synthesized based on Sillman et al. to generate a high drug content formulation, a two-step solvent displacement experimental set up was designed. The first step was designed to formulate a MDTG nanocrystal emulsion, and the second step was designed to coat the nanocrystal with a minimal mass of a polymeric nanocarrier. The formulation developed through a coating method has a fast release of compound, as 100% of the payload gets released before 2 hours. This work provides evidence that a substantial percentage of the sexually active population, may find themselves in an unplanned low to moderate risk scenario for sexual HIV acquisition. A potential solution for this population may lie in a localised nanoparticle delivery system to the vaginal or anal tissue (Chapter 4). In this work, proof of concept of coating an MDTG nanocrystal for this purpose was achieved. However, the drug release profile is not ideal for PEPSE purposes, thus future research is needed to perfect such a delivery system.

Published
2022

5. Advancing co-production for transformative change by synthesizing guidance from case studies on the sustainable management and governance of natural resources

Author

van Maurik Matuk, Fernanda A., Verschuuren, Bas, Morseletto, Piero, Krause, Torsten, Ludwig, David, Cooke, Steven J., Haverroth, Moacir, Maeesters, Marieke, Mattijssen, Thomas J.M., Keßler, Sabine, Lanza, Tomaz R., Milberg, Esther, Ming, Lin Chau, Hernández-Vélez, Carlos Alberto, da Silva, Késia Mara T., Souza, Marcos Paulo V., Souza, Vanessa Oliveira, Fernandes, Jackson Washington, and dos Reis Carvalho, Bruna L.

Published
2023
Full Text
View/download PDF

6. Existence and Morse Index of least energy nodal solution of the $(p,2)$-laplacian

Author

Agudelo, Oscar, Restrepo, Daniel, and Velez, Carlos

Subjects
Mathematics - Analysis of PDEs
Abstract

In this paper we study the quasilinear equation $- \ep^2 \Delta u-\Delta_p u=f(u)$ in a smooth bounded domain $\Omega$ with Dirichlet boundary condition. For $\ep \geq 0$, we review existence of a least energy nodal solution and then present information about the Morse Index of least nodal energy solutions this BVP. In particular we provide Morse Index information for the case $\ep =0$., Comment: 37 pages, no figures

Published
2018

8. Simulation of the Physicochemical Properties of Anatase TiO2 with Oxygen Vacancies and Doping of Different Elements for Photocatalysis Processes

Author

Heredia-Ureta, Heraclio, Torres, Ana E., Reguera, Edilso F., Aguirre-Vélez, Carlos I., Kacprzyk, Janusz, Series Editor, Gomide, Fernando, Advisory Editor, Kaynak, Okyay, Advisory Editor, Liu, Derong, Advisory Editor, Pedrycz, Witold, Advisory Editor, Polycarpou, Marios M., Advisory Editor, Rudas, Imre J., Advisory Editor, Wang, Jun, Advisory Editor, Botto-Tobar, Miguel, editor, S. Gómez, Omar, editor, Rosero Miranda, Raul, editor, Díaz Cadena, Angela, editor, Montes León, Sergio, editor, and Luna-Encalada, Washington, editor

Published
2022
Full Text
View/download PDF

9. Multiplicity results and qualitative properties for semilinear elliptic problems with Neumann boundary conditions

Author

Agudelo, Oscar, Correa, Santiago, Restrepo, Daniel, and Velez, Carlos

Subjects
Mathematics - Analysis of PDEs
Abstract

In this paper we study multiplicity and qualitative behavior of solutions for semilinear elliptic problems with neumann boundary condition and asymptotically linear smooth nonlinearity. We provide sufficient conditions on the number of eigenvalues the derivative of the nonlinearity crosses to guarantee existence of at least five nontrivial solutions. The techniques we use are a combination of minimization, Leray-Schauder degree, Morse Theory and Reduction method a la Castro-Lazer.

Published
2018

13. Existence of multiple solutions for a quasilinear elliptic problem

Author

Cossio, Jorge, Herrón, Sigifredo, and Vélez, Carlos

Subjects
Mathematics - Analysis of PDEs
Abstract

In this paper we prove the existence of multiple solutions for a quasilinear elliptic boundary value problem, when the p-derivative at zero and the p-derivative at infinity of the nonlinearity are greater than the first eigenvalue of the p-Laplace operator. Our proof uses bifurcation from infinity and bifurcation from zero to prove the existence of unbounded branches of positive solutions (resp. of negative solutions). We show the existence of multiple solutions and we provide qualitative properties of these solutions.

Published
2016

14. Performance of Xpert MTB/RIF and Mycobacterial Culture on Multiple Specimen Types for Diagnosis of Tuberculosis Disease in Young Children and Clinical Characterization According to Standardized Research Case Definitions

Author

Click, Eleanor S., Song, Rinn, Smith, Jonathan P., Mchembere, Walter, Fajans, Mark, Hariri, Parisa, Okeyo, Elisha, McCarthy, Kimberly D., Gethi, Dickson, Odeny, Lazarus, Musau, Susan, Okumu, Albert, Orwa, James, Perez-Velez, Carlos M., Wright, Colleen A., Andres, Mariaem M., Marais, Ben J., Schaaf, H. Simon, Graham, Stephen M., Cruz, Andrea T., and Cain, Kevin P.

Published
2022
Full Text
View/download PDF

17. A Blueprint to Address Research Gaps in the Development of Biomarkers for Pediatric Tuberculosis

Author

Nicol, Mark Patrick, Gnanashanmugam, Devasena, Browning, Renee, Click, Eleanor S, Cuevas, Luis E, Detjen, Anne, Graham, Steve M, Levin, Michael, Makhene, Mamodikoe, Nahid, Payam, Perez-Velez, Carlos M, Reither, Klaus, Song, Rinn, Spiegel, Hans ML, Worrell, Carol, Zar, Heather J, and Walzl, Gerhard

Subjects
Prevention, Infectious Diseases, Tuberculosis, Pediatric, Rare Diseases, Pediatric Research Initiative, Infection, Good Health and Well Being, Biological Specimen Banks, Biomarkers, Biomedical Research, Child, Delivery of Health Care, Humans, National Institutes of Health (U.S.), Pediatrics, Specimen Handling, United States, tuberculosis, children, diagnosis, biomarker, blueprint, Biological Sciences, Medical and Health Sciences, Microbiology
Abstract

Childhood tuberculosis contributes significantly to the global tuberculosis disease burden but remains challenging to diagnose due to inadequate methods of pathogen detection in paucibacillary pediatric samples and lack of a child-specific host biomarker to identify disease. Accurately diagnosing tuberculosis in children is required to improve case detection, surveillance, healthcare delivery, and effective advocacy. In May 2014, the National Institutes of Health convened a workshop including researchers in the field to delineate priorities to address this research gap. This blueprint describes the consensus from the workshop, identifies critical research steps to advance this field, and aims to catalyze efforts toward harmonization and collaboration in this area.

Published
2015

20. Tpwards a Comprehensive Understanding of DIRT PICKUP RESISTANCE

Author

Brown, Scoff C., Diebold, Michael, Kraiter, Daniel, Velez, Carlos, and Jernakoff, Peter

Subjects
Surfaces (Materials) -- Mechanical properties -- Usage -- Environmental aspects, Coatings -- Usage -- Market research, Adhesion (Surface science) -- Environmental aspects -- Mechanical properties -- Usage, Particulate matter -- Control -- Usage -- Environmental aspects -- Mechanical properties, Coatings industry -- Market research, Marketing research, Business, Chemicals, plastics and rubber industries
Abstract

The fouling of exterior coating surfaces by dirt is no simple matter. The process is complex, dynamic, and varies in length and time. It also includes a range of confounding [...]

Published
2020

25. Promoting Learning and Educational Delivery and Quality among 'At Risk' U.S. Mexican and Native American Elementary School Children in Tucson, Arizona. A Pilot Project.

Author

Ibanez-Velez, Carlos

Abstract

This report summarizes a pilot project that used home cultural resources and activities in promoting learning and enhancing educational delivery to at-risk U.S. Mexican and Native American elementary school children in grades three through six. Hollinger, C.E. Rose, and Lawrence Elementary schools (Arizona) were the at-risk sites chosen for the study. Eleven teachers from the three schools participated in weekly training sessions in basic ethnographic and anthropological methodology at the University of Arizona. Field work experience involved the selection of 3 target households by each teacher for a total of 97 household observations. Field notes followed a prepared questionnaire that emphasized the household's labor history and "funds of knowledge". "Funds of knowledge" are the array of skills, survival strategies, and home practices that may be utilized by the classroom teacher to appropriately contextualize mathematics, comprehension, and composition lessons. From this information learning modules were constructed and successfully taught to the students. Teachers attributed their successful participation within the households as a result of their anthropological training. Complete descriptions of project implementation and the approach used in accessing the Yaqui Community are included. Attachments include the project proposal and the project evaluation questionnaire. (LP)

Published
1991

26. Parallel Ant Colony Optimization for the HP Protein Folding Problem

Author

Llanes, Antonio, Vélez, Carlos, Sánchez, Antonia M., Pérez-Sánchez, Horacio, Cecilia, José M., Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Ortuño, Francisco, editor, and Rojas, Ignacio, editor

Published
2016
Full Text
View/download PDF

32. Severe Enteropathy and Hypogammaglobulinemia Complicating Refractory Mycobacterium tuberculosis Complex Disseminated Disease in a Child with IL-12Rβ1 Deficiency

Author

Arias, Andrés Augusto, Perez-Velez, Carlos M., Orrego, Julio César, Moncada-Velez, Marcela, Rojas, Jessica Lineth, Wilches, Alejandra, Restrepo, Andrea, Trujillo, Mónica, Garcés, Carlos, Arango-Ferreira, Catalina, González, Natalia, Oleaga-Quintas, Carmen, Fernández, Diana, Isaza-Correa, Johana Marcela, Gongóra, Diego Eduardo, Gonzalez-Loaiza, Daniel, Sierra, Juan Esteban, Casanova, Jean Laurent, Bustamante, Jacinta, and Franco, José Luis

Published
2017
Full Text
View/download PDF

35. The Contribution of Chest Radiography to the Clinical Management of Children Exposed to Tuberculosis

Author

Huang, Chuan-Chin, primary, Tan, Qi, additional, Becerra, Mercedes C., additional, Calderon, Roger, additional, Chiang, Silvia S., additional, Contreras, Carmen, additional, Lecca, Leonid, additional, Jimenez, Judith, additional, Perez-Velez, Carlos M., additional, Roya-Pabon, Claudia L., additional, Yataco, Rosa, additional, Xu, Hai, additional, Zhang, Zibiao, additional, and Murray, Megan, additional

Published
2022
Full Text
View/download PDF

41. Analysis of Prevalence and Predictive Factors of Long-Lasting Olfactory and Gustatory Dysfunction in COVID-19 Patients

Author

Callejón-Leblic, María A., primary, Martín-Jiménez, Daniel I., additional, Moreno-Luna, Ramón, additional, Palacios-Garcia, Jose M., additional, Alvarez-Cendrero, Marta, additional, Vizcarra-Melgar, Julissa A., additional, Fernandez-Velez, Carlos, additional, Reyes-Tejero, Isabel M., additional, Maza-Solano, Juan, additional, Gonzalez-Garcia, Jaime, additional, Tena-García, Beatriz, additional, Acosta-Mosquera, María E., additional, Del Cuvillo, Alfonso, additional, and Sánchez-Gómez, Serafín, additional

Published
2022
Full Text
View/download PDF

50. Clinical Outcomes of Monoclonal Antibody Therapy During a COVID ‐19 Outbreak in a Skilled Nursing Facility‐Arizona, 2021

Author

Dale, Ariella P., primary, Hudson, Matthew J., additional, Armenta, Darunee, additional, Friebus, Heather, additional, Ellingson, Katherine D., additional, Davis, Kat, additional, Cullen, Theresa, additional, Brady, Shane, additional, Komatsu, Kenneth K., additional, Stone, Nimalie D., additional, Uyeki, Timothy M., additional, Slifka, Kara Jacobs, additional, Perez‐Velez, Carlos M., additional, and Keaton, Amelia A., additional

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results