http://sedici.unlp.edu.ar:80/handle/10915/123374 Fri, 30 Oct 2026 20:20:21 GMT 2026-10-30T20:20:21Z http://sedici.unlp.edu.ar:80/handle/10915/196945 Articulo Ludovica Pediátrica; vol. 28, no. 1 Introducción: El vínculo madre-lactante es el que se establece entre la madre y el bebé. Engloba a la comunicación y es el producto de un proceso comunicacional continuo. Para díadas sin dificultades en el desarrollo se utiliza la Escala de Observación del Vínculo Madre-Bebé. Dado que los lactantes con Síndrome de Down (SD) presentan mayores dificultades en el desarrollo, resulta necesario contar con instrumentos específicamente adaptados. El objetivo fue analizar la validez de contenido del perfil 1 de la escala mediante el juicio de expertos, para su uso en díadas madre-lactante con SD entre 0 y 8 meses. Material y métodos: Se realizó un estudio descriptivo con diseño mixto. Profesionales expertos con experiencia clínica evaluaron cada ítem de la escala según los criterios de suficiencia, claridad, coherencia y relevancia. Además, se recopilaron sugerencias cualitativas. El análisis cuantitativo incluyó el coeficiente V de Aiken por ítem y Kappa de Fleiss por criterio. Para los datos cualitativos se realizó el análisis temático de Braun y Clarke. El procesamiento estadístico se realizó con el software R versión 4.3.1 y SPSS versión 26. Resultados: Participaron 29 profesionales de diversas disciplinas. La mayoría de los ítems de la escala obtuvieron un V de Aiken ≥ 0,70 con significación (p < 0,05) para suficiencia, claridad, coherencia y relevancia, excepto la función sostén (V = 0,59; p = 0,229). El Kappa de Fleiss indicó concordancia leve en suficiencia (K = 0,19), moderado en claridad (K = 0,59) y sustancial en coherencia (K = 0,61) y relevancia (K = 0,70). El análisis temático identificó ajustes necesarios en todas las dimensiones, especialmente para la función sostén. Conclusión: El análisis de la validez de contenido basado en el juicio de expertos respalda la revisión y adaptación de la Escala de Observación del Vínculo Madre-Bebé para lactantes con Síndrome de Down.; Introduction: The mother-infant bond refers to the relationship established between the mother and her baby. It encompasses communication and is the result of a continuous communicational process. The Mother-Infant Bond Observation Scale was originally designed for dyads without developmental difficulties. Given that infants with Down syndrome (DS) are at increased risk of developing conditions that may compromise their development, it is essential to have instruments specifically adapted to this population. The aim of this study was to analyze the content validity of profile 1 of the scale through expert judgment, for its use with mother-infant dyads with DS between 0 and 8 months. Materials and Methods: A descriptive study with a mixed-methods design was conducted. Professional experts with clinical experience evaluated each item of the scale according to the criteria of sufficiency, clarity, coherence, and relevance. Qualitative suggestions were also collected. Quantitative analysis included Aiken’s V coefficient per item and Fleiss’ Kappa per criterion. Qualitative data were analyzed using the thematic analysis approach by Braun and Clarke. Statistical processing was performed using R version 4.3.1 and SPSS version 26. Results: Twenty-nine professionals from various disciplines participated. Most items obtained Aiken’s V ≥ 0.70 with statistical significance (p < 0.05) for sufficiency, clarity, coherence, and relevance, except for the holding function (V = 0.59; p = 0.229). Fleiss’ Kappa indicated slight agreement for sufficiency (K = 0.19), moderate for clarity (K = 0.59), and substantial for coherence (K = 0.61) and relevance (K = 0.70). Thematic analysis identified necessary adjustments in all dimensions, particularly regarding the holding function. Conclusion: The analysis of content validity based on expert judgment supports the revision and adaptation of the Mother-Baby Bond Observation Scale for infants with Down syndrome. Tue, 01 Jul 2025 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/196945 2025-07-01T00:00:00Z Introducción: El vínculo madre-lactante es el que se establece entre la madre y el bebé. Engloba a la comunicación y es el producto de un proceso comunicacional continuo. Para díadas sin dificultades en el desarrollo se utiliza la Escala de Observación del Vínculo Madre-Bebé. Dado que los lactantes con Síndrome de Down (SD) presentan mayores dificultades en el desarrollo, resulta necesario contar con instrumentos específicamente adaptados. El objetivo fue analizar la validez de contenido del perfil 1 de la escala mediante el juicio de expertos, para su uso en díadas madre-lactante con SD entre 0 y 8 meses. Material y métodos: Se realizó un estudio descriptivo con diseño mixto. Profesionales expertos con experiencia clínica evaluaron cada ítem de la escala según los criterios de suficiencia, claridad, coherencia y relevancia. Además, se recopilaron sugerencias cualitativas. El análisis cuantitativo incluyó el coeficiente V de Aiken por ítem y Kappa de Fleiss por criterio. Para los datos cualitativos se realizó el análisis temático de Braun y Clarke. El procesamiento estadístico se realizó con el software R versión 4.3.1 y SPSS versión 26. Resultados: Participaron 29 profesionales de diversas disciplinas. La mayoría de los ítems de la escala obtuvieron un V de Aiken ≥ 0,70 con significación (p < 0,05) para suficiencia, claridad, coherencia y relevancia, excepto la función sostén (V = 0,59; p = 0,229). El Kappa de Fleiss indicó concordancia leve en suficiencia (K = 0,19), moderado en claridad (K = 0,59) y sustancial en coherencia (K = 0,61) y relevancia (K = 0,70). El análisis temático identificó ajustes necesarios en todas las dimensiones, especialmente para la función sostén. Conclusión: El análisis de la validez de contenido basado en el juicio de expertos respalda la revisión y adaptación de la Escala de Observación del Vínculo Madre-Bebé para lactantes con Síndrome de Down. Introduction: The mother-infant bond refers to the relationship established between the mother and her baby. It encompasses communication and is the result of a continuous communicational process. The Mother-Infant Bond Observation Scale was originally designed for dyads without developmental difficulties. Given that infants with Down syndrome (DS) are at increased risk of developing conditions that may compromise their development, it is essential to have instruments specifically adapted to this population. The aim of this study was to analyze the content validity of profile 1 of the scale through expert judgment, for its use with mother-infant dyads with DS between 0 and 8 months. Materials and Methods: A descriptive study with a mixed-methods design was conducted. Professional experts with clinical experience evaluated each item of the scale according to the criteria of sufficiency, clarity, coherence, and relevance. Qualitative suggestions were also collected. Quantitative analysis included Aiken’s V coefficient per item and Fleiss’ Kappa per criterion. Qualitative data were analyzed using the thematic analysis approach by Braun and Clarke. Statistical processing was performed using R version 4.3.1 and SPSS version 26. Results: Twenty-nine professionals from various disciplines participated. Most items obtained Aiken’s V ≥ 0.70 with statistical significance (p < 0.05) for sufficiency, clarity, coherence, and relevance, except for the holding function (V = 0.59; p = 0.229). Fleiss’ Kappa indicated slight agreement for sufficiency (K = 0.19), moderate for clarity (K = 0.59), and substantial for coherence (K = 0.61) and relevance (K = 0.70). Thematic analysis identified necessary adjustments in all dimensions, particularly regarding the holding function. Conclusion: The analysis of content validity based on expert judgment supports the revision and adaptation of the Mother-Baby Bond Observation Scale for infants with Down syndrome. http://sedici.unlp.edu.ar:80/handle/10915/194186 Articulo On time-dependent lagrangian systems over lie groups and variational integrators XLI Congreso Argentino de Mecánica Computacional (Buenos Aires, 11 al 14 de noviembre de 2025); Mecánica Computacional; vol. 42, no. 7 Los sistemas Lagrangianos mecánicos dependientes del tiempo son de gran interés en diversas ramas de la ingeniería y la física. En particular, en robótica, se consideran numerosos sistemas no autónomos, es decir, dependientes del tiempo. En este trabajo presentamos la dinámica de tales sistemas en grupos de Lie, considerando tanto variables temporales continuas como discretas. En este marco, abordamos el problema de integrar sus ecuaciones de movimiento mediante técnicas variacionales discretas. Ilustramos el enfoque con ejemplos sencillos cuyo espacio de configuración es el grupo euclidiano y proponemos sus versiones discretas. Asimismo, estudiamos un ejemplo en el grupo de rotaciones espaciales y, finalmente, discutimos posibles líneas de investigación futura orientadas al desarrollo de integradores variacionales para sistemas más generales.; Time-dependent Lagrangian mechanical systems are of great interest in various branches of engineering and physics. In particular, in robotics, many non-autonomous, that is time-dependent, Lagrangian systems are considered. In this work, we present the dynamics of such systems on Lie groups, considering both continuous and discrete time variables. Within this framework, we address the problem of integrating their equations of motion using discrete variational techniques. We illustrate the approach with simple examples whose configuration space is the Euclidean group, and propose their discrete counterparts. We also study an example on the group of spatial rotations, and finally discuss future research directions aimed at developing variational integrators for more general systems. Wed, 01 Jan 2025 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/194186 2025-01-01T00:00:00Z Los sistemas Lagrangianos mecánicos dependientes del tiempo son de gran interés en diversas ramas de la ingeniería y la física. En particular, en robótica, se consideran numerosos sistemas no autónomos, es decir, dependientes del tiempo. En este trabajo presentamos la dinámica de tales sistemas en grupos de Lie, considerando tanto variables temporales continuas como discretas. En este marco, abordamos el problema de integrar sus ecuaciones de movimiento mediante técnicas variacionales discretas. Ilustramos el enfoque con ejemplos sencillos cuyo espacio de configuración es el grupo euclidiano y proponemos sus versiones discretas. Asimismo, estudiamos un ejemplo en el grupo de rotaciones espaciales y, finalmente, discutimos posibles líneas de investigación futura orientadas al desarrollo de integradores variacionales para sistemas más generales. Time-dependent Lagrangian mechanical systems are of great interest in various branches of engineering and physics. In particular, in robotics, many non-autonomous, that is time-dependent, Lagrangian systems are considered. In this work, we present the dynamics of such systems on Lie groups, considering both continuous and discrete time variables. Within this framework, we address the problem of integrating their equations of motion using discrete variational techniques. We illustrate the approach with simple examples whose configuration space is the Euclidean group, and propose their discrete counterparts. We also study an example on the group of spatial rotations, and finally discuss future research directions aimed at developing variational integrators for more general systems. http://sedici.unlp.edu.ar:80/handle/10915/160459 Articulo VIII MACI 2021 (La Plata, 3 al 7 de mayo de 2021); Matemática Aplicada, Computacional e Industrial (MACI); vol. 8 Un grafo de intersección por aristas de una familia de caminos en un árbol huesped es llamado grafo EPT. Cuando el grado máximo del árbol huesped es 4, decimos que el grafo es [4, 2, 2]. En este trabajo, consideramos el problema de clique coloración en grafos [4,2, 2]. Probamos que esta clase de grafos es 3-clique coloreable y damos ejemplos de grafos en esta clase que no son 2-clique coloreables. Además, estudiamos subclases de grafos en [4, 2,2] que tienen número clique cromático menor o igual a 2. Fri, 01 Jan 2021 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/160459 2021-01-01T00:00:00Z Un grafo de intersección por aristas de una familia de caminos en un árbol huesped es llamado grafo EPT. Cuando el grado máximo del árbol huesped es 4, decimos que el grafo es [4, 2, 2]. En este trabajo, consideramos el problema de clique coloración en grafos [4,2, 2]. Probamos que esta clase de grafos es 3-clique coloreable y damos ejemplos de grafos en esta clase que no son 2-clique coloreables. Además, estudiamos subclases de grafos en [4, 2,2] que tienen número clique cromático menor o igual a 2. http://sedici.unlp.edu.ar:80/handle/10915/139126 Articulo Order; vol. 38, no. 2 A k-tree is either a complete graph on k vertices or a graph that contains a vertex whose neighborhood induces a complete graph on k vertices and whose removal results in a k-tree. If the comparability graph of a poset P is a k-tree, we say that P is a k-tree poset. In the present work, we study and characterize by forbidden subposets the k-tree posets that admit a containment model mapping vertices into paths of a tree (CPT k-tree posets). Furthermore, we characterize the dually-CPT and strong-CPT k-tree posets and their comparability graphs. The characterizations lead to efficient recognition algorithms for the respective classes. Sat, 22 Aug 2020 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/139126 2020-08-22T00:00:00Z A k-tree is either a complete graph on k vertices or a graph that contains a vertex whose neighborhood induces a complete graph on k vertices and whose removal results in a k-tree. If the comparability graph of a poset P is a k-tree, we say that P is a k-tree poset. In the present work, we study and characterize by forbidden subposets the k-tree posets that admit a containment model mapping vertices into paths of a tree (CPT k-tree posets). Furthermore, we characterize the dually-CPT and strong-CPT k-tree posets and their comparability graphs. The characterizations lead to efficient recognition algorithms for the respective classes. http://sedici.unlp.edu.ar:80/handle/10915/138133 Contribucion a revista Journal of Fourier Analysis and Applications; vol. 26, no. 4 We study the Heil–Ramanathan–Topiwala conjecture in Lp spaces by reformulating it as a fixed point problem. This reformulation shows that a function with linearly dependent time–frequency translates has a very rigid structure, which is encoded in a family of linear operators. This is used to give an elementary proof that if f∈Lp(R), p∈[1,2], and Λ⊆R×R is contained in a lattice then the set of time frequency translates (f(a,b))(a,b)∈Λ is linearly independent. Our proof also works for the case 2 < p < ∞ if Λ is contained in a lattice of the form αZ×βZ. Wed, 01 Jan 2020 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/138133 2020-01-01T00:00:00Z We study the Heil–Ramanathan–Topiwala conjecture in Lp spaces by reformulating it as a fixed point problem. This reformulation shows that a function with linearly dependent time–frequency translates has a very rigid structure, which is encoded in a family of linear operators. This is used to give an elementary proof that if f∈Lp(R), p∈[1,2], and Λ⊆R×R is contained in a lattice then the set of time frequency translates (f(a,b))(a,b)∈Λ is linearly independent. Our proof also works for the case 2 < p < ∞ if Λ is contained in a lattice of the form αZ×βZ. http://sedici.unlp.edu.ar:80/handle/10915/125545 Preprint Discrete Applied Mathematics A graph G is a B₀-VPG graph if one can associate a horizontal or vertical path on a rectangular grid with each vertex such that two vertices are adjacent if and only if the corresponding paths intersect in at least one grid-point. A graph G is a contact B₀-VPG graph if it is a B₀-VPG graph admitting a representation with no one-point paths, no two paths crossing, and no two paths sharing an edge of the grid. In this paper, we present a minimal forbidden induced subgraph characterisation of contact B₀-VPG graphs within four special graph classes: chordal graphs, tree-cographs, P₄-tidy graphs and P5-free graphs. Moreover, we present a polynomial-time algorithm for recognising chordal contact B₀-VPG graphs. Tue, 01 Jan 2019 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/125545 2019-01-01T00:00:00Z A graph G is a B₀-VPG graph if one can associate a horizontal or vertical path on a rectangular grid with each vertex such that two vertices are adjacent if and only if the corresponding paths intersect in at least one grid-point. A graph G is a contact B₀-VPG graph if it is a B₀-VPG graph admitting a representation with no one-point paths, no two paths crossing, and no two paths sharing an edge of the grid. In this paper, we present a minimal forbidden induced subgraph characterisation of contact B₀-VPG graphs within four special graph classes: chordal graphs, tree-cographs, P₄-tidy graphs and P5-free graphs. Moreover, we present a polynomial-time algorithm for recognising chordal contact B₀-VPG graphs. http://sedici.unlp.edu.ar:80/handle/10915/125209 Preprint Communications in Contemporary Mathematics; 2020 In this paper we study two deformation procedures for quantum groups: deformations by twists, that we call "comultiplication twisting", as they modify the coalgebra structure, while keeping the algebra one -- and deformations by 2-cocycle, that we call "multiplication twisting", as they deform the algebra structure, but save the coalgebra one. We deal with quantum universal enveloping algebras, in short QUEA's, for which we accordingly consider those arising from twisted deformations (in short TwQUEA's) and those arising from 2-cocycle deformations, usually called multiparameter QUEA's (in short MpQUEA's). Up to technicalities, we show that the two deformation methods are equivalent, in that they eventually provide isomorphic outputs, which are deformations (of either kinds) of the "canonical", well-known one-parameter QUEA by Jimbo and Lusztig. It follows that the two notions of TwQUEA's and of MpQUEA's -- which, in Hopf algebra theoretical terms are naturally dual to each other -- actually coincide; thus, that there exists in fact only one type of "pluriparametric deformation" for QUEA's. In particular, the link between the realization of any such QUEA as a MpQUEA and that as a TwQUEA is just a (very simple, and rather explicit) change of presentation. Wed, 01 Jan 2020 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/125209 2020-01-01T00:00:00Z In this paper we study two deformation procedures for quantum groups: deformations by twists, that we call "comultiplication twisting", as they modify the coalgebra structure, while keeping the algebra one -- and deformations by 2-cocycle, that we call "multiplication twisting", as they deform the algebra structure, but save the coalgebra one. We deal with quantum universal enveloping algebras, in short QUEA's, for which we accordingly consider those arising from twisted deformations (in short TwQUEA's) and those arising from 2-cocycle deformations, usually called multiparameter QUEA's (in short MpQUEA's). Up to technicalities, we show that the two deformation methods are equivalent, in that they eventually provide isomorphic outputs, which are deformations (of either kinds) of the "canonical", well-known one-parameter QUEA by Jimbo and Lusztig. It follows that the two notions of TwQUEA's and of MpQUEA's -- which, in Hopf algebra theoretical terms are naturally dual to each other -- actually coincide; thus, that there exists in fact only one type of "pluriparametric deformation" for QUEA's. In particular, the link between the realization of any such QUEA as a MpQUEA and that as a TwQUEA is just a (very simple, and rather explicit) change of presentation. http://sedici.unlp.edu.ar:80/handle/10915/123376 Articulo Journal of Fourier Analysis and Applications; vol. 25, no. 4 We solve the problem of best approximation by Parseval frames to an arbitrary frame in a subspace of an infinite dimensional Hilbert space. We explicitly describe all the solutions and we give a criterion for uniqueness. Our proof relies on the geometric structure of the set of all Parseval frames quadratically close to a given frame. In the process we show that its connected components can be parametrized by using the notion of index of a pair of projections, and we prove existence and uniqueness results of best approximation by Parseval frames restricted to these connected components. Thu, 26 Jul 2018 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/123376 2018-07-26T00:00:00Z We solve the problem of best approximation by Parseval frames to an arbitrary frame in a subspace of an infinite dimensional Hilbert space. We explicitly describe all the solutions and we give a criterion for uniqueness. Our proof relies on the geometric structure of the set of all Parseval frames quadratically close to a given frame. In the process we show that its connected components can be parametrized by using the notion of index of a pair of projections, and we prove existence and uniqueness results of best approximation by Parseval frames restricted to these connected components. http://sedici.unlp.edu.ar:80/handle/10915/75207 Articulo Revista de Educación Matemática; vol. 34, no. 1 En este artículo describimos la conformación de un equipo de trabajo entre miembros de diferentes unidades académicas de la Universidad Nacional de La Plata (UNLP) y el proceso de problematización que fuimos transitando para construir conocimiento sobre la enseñanza de la matemática en aulas del nivel universitario que incluyen a estudiantes sordos. Si bien la Comisión Universitaria sobre Discapacidad de la UNLP asigna intérpretes en Lengua de Señas Argentina –quienes acompañan a los alumnos durante las clases–, este apoyo parece no resultar suficiente para lograr la retención y el avance de los alumnos en la construcción de aprendizajes matemáticos. Nuestro proyecto propone la conformación de un espacio institucional específico en el que sus distintos actores participen en la identificación de barreras, así como en la construcción de apoyos para la inclusión.; In this article, we describe the conformation of a work team between members of different academic units of Universidad Nacional de La Plata (UNLP), and the problematization process that we were going through to build knowledge about the teaching of mathematics in classrooms at a university level that includes deaf students. The University Commission on Disability of the UNLP assigns interpreters in Argentinean Sign Language –which accompany the students during the classes–, but this support does not seem to result enough to achieve the retention and advancement of students in the construction of mathematics learning. Our project proposes the conformation of a specific institutional space in which different actors participate in the identification of barriers, as well as in the construction of supports for inclusion. Tue, 07 May 2019 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/75207 2019-05-07T00:00:00Z En este artículo describimos la conformación de un equipo de trabajo entre miembros de diferentes unidades académicas de la Universidad Nacional de La Plata (UNLP) y el proceso de problematización que fuimos transitando para construir conocimiento sobre la enseñanza de la matemática en aulas del nivel universitario que incluyen a estudiantes sordos. Si bien la Comisión Universitaria sobre Discapacidad de la UNLP asigna intérpretes en Lengua de Señas Argentina –quienes acompañan a los alumnos durante las clases–, este apoyo parece no resultar suficiente para lograr la retención y el avance de los alumnos en la construcción de aprendizajes matemáticos. Nuestro proyecto propone la conformación de un espacio institucional específico en el que sus distintos actores participen en la identificación de barreras, así como en la construcción de apoyos para la inclusión. In this article, we describe the conformation of a work team between members of different academic units of Universidad Nacional de La Plata (UNLP), and the problematization process that we were going through to build knowledge about the teaching of mathematics in classrooms at a university level that includes deaf students. The University Commission on Disability of the UNLP assigns interpreters in Argentinean Sign Language –which accompany the students during the classes–, but this support does not seem to result enough to achieve the retention and advancement of students in the construction of mathematics learning. Our project proposes the conformation of a specific institutional space in which different actors participate in the identification of barriers, as well as in the construction of supports for inclusion.