Invited Lectures 
2007 
The generic inverse problem in differential Galois theory, Séminaire d'Arithmétique, Laboratoire d'Arithmétique et d'Algèbre, Université Jean Monnet, SaintEtienne, France, June 19.  
SO_{3}torsors: classification and construction of differential equations, Séminaire de Calcul formel et Complexité, IRMAR, Rennes, France, May 23.  
Generic PicardVessiot extensions,Workshop on Arithmetic and Differential Galois Groups, Oberwolfach, Germany, May 14.  
Differential Central Simple Algebras and Noncommutative PicardVessiot Cocycles, Special Session on Differential Algebra and related topics, AMS Eastern Section Meeting, Stevens Institute of Technology, Hoboken, NJ, April 14. 
2006 
(Sponsored by an AWM travel grant.) Three talks at the Kolchin Seminar in Differential Algebra, Hunter College and Graduate College Series, City University of New York:

2005 
Generic PicardVessiot extensions for connectedbyfinite groups, Kolchin Seminar in Differential Algebra, Hunter College Series, City University of New York, October 22.  
Generic PicardVessiot extensions and generic equations, Special session on Classical and Differential Galois Theory, AMS 2005 Spring Central Section Meeting, Lubbock, April 9. 
2004 
Generic differential Galois extensions, Algebra Seminar, University of Texas at Austin, February 24. 
2003 
A generic approach to the inverse differential Galois problem , Two hour talk, Kolchin Seminar in Differential Algebra featured speaker, Hunter College, City University of New York, November 15.  
Generic PicardVessiot extensions and examples, First Joint Meeting between the Real Sociedad Matemática Española and the American Mathematical Society, Seville, Spain, June 20th, (Participation sponsored by an Association of Women in Mathematics travel grant).  
Generic PicardVessiot extensions for connected linear algebraic groups, INRIA, Nice SophiaAntipolis, France, June 4th (Visit to INRIA sponsored by the project CAFE). 
2002 
Generic PicardVessiot Extensions and generic linear differential equations with group G. , Kolchin Seminar in Differential Algebra, Hunter College, City University of New York, December 15.  
An application of Computer Algebra to Differential Galois Theory, Poster, East Coast Computer Algebra Day, La Guardia Community College, Long Island City, New York, May 18 (Participation sponsored by ECCAD 2002).  
Pure PicardVessiot extensions with generic properties, Kolchin Seminar in Differential Algebra. City College of New York, City University of New York, February 2.  
Pure PicardVessiot extensions with generic properties, Special Session on Algebras, Forms, and Algebraic Groups, Joint Mathematics Meetings, San Diego, January 8. 
2001 
Generic PicardVessiot extensions for connected linear algebraic groups with trivial Galois cohomology, Kolchin Seminar in Differential Algebra. City College of New York, City University of New York, October 21.  
Generic PicardVessiot extensions and generic operators, Geometry and Analysis Seminar. Department of Mathematics. Texas Tech University, May 4.  
The generic inverse differential Galois problem for linear algebraic groups, Kolchin Seminar in Differential Algebra. City College of New York, City University of New York, March 17.  
Generic PicardVessiot extensions with group G, MSRI Seminar, February 23.  
A generic inverse differential Galois
problem for GLn,

2000 
On a generic inverse differential Galois problem for GLn, Columbia University, New York, AMS Eastern Section Meeting, November 4.  
On the inverse differential Galois Problem for GLn, San Francisco State University, California, AMS Western Section Meeting, October 21.  
A generic PicardVessiot extension with group GLn,
Commutative and Noncommutative Algebra and Algebraic Geometry Seminar,
 
A Generic PicardVessiot Extension for GLn and the Inverse Differential Galois Problem, 106th Annual Meeting of the AMS, Washington, DC, January 22. 
1998 
Fitting Graphs in Surfaces, Pi Mu Epsilon Math Awareness Week, University of Oklahoma, April 20.  
Gröbner Bases, Series of two talks in the Algebra Seminar, Department of Mathematics, University of Oklahoma, Spring.  
On a Theorem of Belyi, Algebra Seminar, Department of Mathematics, University of Oklahoma, Fall. 
1997 
The RiemannRoch Theorem for Algebraic Curves, Series of five talks in the Algebra Seminar, Department of Mathematics, University of Oklahoma, Spring.  
The Galois Group of a Differential Equation, Series of two talks in the Algebra Seminar, Department of Mathematics, University of Oklahoma, Fall 
1993 
Intensional Expert Systems, Universidad Michoacana de San Nicolas de Hidalgo, Mexico, November 8.  
Probabilistic Models in Knowledge Representation, Center for Mathematical Research (CIMAT), Guanajuato, Mexico, October 26.  
The Role of Uncertainty in Knowledge Representation, Week of Mathematics in the festivities for the 20th Aniversary of the the B.S. in Mathematics at La Benemerita Universidad Autonoma de Puebla (BUAP), Mexico, October 25.  
Intensional Systems to Represent Uncertainty in Expert Systems, Institute of Applied Mathematics (IMAS) UNAM, Mexico City, October 12.  
Series
of three lectures at the section of Computer Sciences, Department of Electrical
Engineering, CINVESTAVIPN, Mexico City, September 2022:
 
Jeffrey's Rule and the Problem of the Autonomous Agents, X National Meeting of the Mexican Society of Artificial Intelligence, ITAM, Mexico City, September.  
Symmetric Semigroups and Almost Arithmetic Sequences, XI Latinamerican School of Mathematics, UNAM, Mexico City, and CIMAT, Guanajuato, Mexico, August 1627. 
1992 
Some Results About Symmetric Semigroups, Second Symposium on the Development of Mathematics, Academy of Sciences of Cuba, September 2125. 
1990 
Korovkin Type Theorems for Sequences of Class JMR, (Poster), Second Student Scientific Forum of the University of Havana, May 5.  
Korovkin Type Theorems for Sequences of Class JMR, First Symposium About the Development of Mathematics, Palace of Congress, Havana, April 25.  