diff --git a/data/comites.yml b/data/comites.yml
index 8fb7cb5..75a33aa 100644
--- a/data/comites.yml
+++ b/data/comites.yml
@@ -3,7 +3,7 @@
   integrantes:
   - nombre: Andrés Navas
     afiliacion: USACH, Chile, UNAM México
-    rol: Presidente
+    rol: Coordinador
   - nombre: María Julia Redondo
     afiliacion: Universidad Nacional del Sur, Argentina
     rol: ''
diff --git a/data/conferencias.yml b/data/conferencias.yml
index cd25e35..fa670f2 100644
--- a/data/conferencias.yml
+++ b/data/conferencias.yml
@@ -259,8 +259,8 @@
     zoom: https://us02web.zoom.us/j/85886767816
     start: 2021-09-16T14:00-0300
     end: 2021-09-16T15:00-0300
-  - titulo: TBA
-    abstract: TBA    
+  - titulo: Mating quadratic maps with the modular group.
+    abstract: 'Holomorphic correspondences are polynomial relations P(z,w)=0, which can be regarded as multi-valued self-maps of the Riemann sphere, this is implicit mapssending z to w. The iteration of such a multi-valued map generates a dynamical system on the Riemann sphere: dynamical system which generalises rational maps and finitely generated Kleinian groups. We consider a specific 1-(complex)parameter family of (2:2) correspondences F_a (introduced by S. Bullett and C. Penrose in 1994), which we describe dynamically. In particular, we show that for every parameter in a subset of the parameter plane called "the connectedness locus" and denoted by M_{\Gamma}, this family behaves as rational maps on a subset of the Riemann sphere and as the modular group on the complement: in other words, these correspondences are mating between the modular group and rational maps (in the family Per_1(1)). Moreover, we develop for this family of correspondences a complete dynamical theory which parallels the Douady-Hubbard theory of quadratic polynomials, and we show that M_{\Gamma} is homeomorphic to the parabolic Mandelbrot set M_1. This is joint work with S. Bullett (QMUL).'
     speaker:
       nombre: Luna Lomonaco
       afiliacion: IMPA, Río de Janeiro, Brasil
@@ -268,8 +268,8 @@
     zoom: https://us02web.zoom.us/j/85886767816
     start: 2021-09-14T14:00-0300
     end: 2021-09-14T15:00-0300   
-  - titulo: TBA
-    abstract: TBA    
+  - titulo: Operadores diferenciales en álgebra.
+    abstract: El anillo de operadores diferenciales, a pesar de no ser conmutativo, ha jugado un papel importante en el desarrollo del álgebra conmutativa en los últimos años. En esta charla nos enfocaremos en su uso para el estudio de singularidades.    
     speaker:
       nombre: Luis Núñez Betancourt
       afiliacion: CIMAT, Guanajuato, México