Early evolutionary differentiation of morphological variation in the mandible of South American caviomorph rodents (Rodentia, Caviomorpha)

Caviomorphs are a clade of South American rodents recorded at least since the early Oligocene (>31.5Ma) that exhibit ample eco-morphological variation. It has been proposed that phylogenetic structure is more important than ecological factors for understanding mandibular shape variation in this clade. This was interpreted as a result of the long-standing evolutionary history of caviomorphs and the early divergence of major lineages. In this work, we test this hypothesis through the analysis of morphological variation in the mandible of living and extinct species and compare this information with that obtained through comparative phylogenetic analyses. Our results support the hypothesis of early origin of mandibular variation; moreover, they suggest the conservation of early differentiated morphologies, which could indicate the existence of constrained evolutionary diversification.Facultad de Ciencias Naturales y Muse

Ecological and phylogenetic influence on mandible shape variation of South American caviomorph rodents (Rodentia: Hystricomorpha)

We analyzed mandible shape variation of 17 genera belonging to three superfamilies (Cavioidea, Chinchilloidea, and Octodontoidea) of South American caviomorph rodents using geometric morphometrics. The relative influence of phylogeny and ecology on this variation was assessed using phylogenetic comparative methods. Most morphological variation was concentrated in condylar, coronoid, and angular processes, as well as the diastema. Features potentially advantageous for digging (i.e. high coronoid and condylar processes, relatively short angular process, and diastema) were present only in octodontoids; cavioids showed opposing trends, which could represent a structural constraint for fossorial habits. Chinchilloids showed intermediate features. Genera were distributed in the morphospace according to their classification into superfamilial clades. The phylogenetic signal for shape components was significant along phylogeny, whereas the relationship between mandibular shape and ecology was nonsignificant when phylogenetic structure was taken into account. An early evolutionary divergence in the mandible shape among major caviomorph clades would explain the observed strong phylogenetic influence on the variation of this structure.Facultad de Ciencias Naturales y Muse

Two- Versus Three-Dimensional Morphometric Approaches in Macroevolution : Insight from the Mandible of Caviomorph Rodents

Morphological variation is one of the most studied dimensions of evolutionary biology, given its close relationship with the ecological aspects of biological diversification. In this work we examine the differences between the use of two- and three-dimensional morphometric techniques for the analysis of macroevolutionary patterns of morphological variation in the mandible of the South American caviomorph rodents, which displays varying degrees of hystricognathy. The variation patterns were similar for 2D and 3D coordinate datasets. However, phylogenetic comparative statistical analyses showed widely different results for mandible variation. Both the phylogenetic signal values and the results of phylogenetic regressions were markedly different between the two macroevolutionary mandible datasets. This suggests that the inclusion of the third coordinate to characterize a hystricognathous mandible may lead to completely different interpretations concerning the processes that could be regulating the morphological diversification of the caviomorph mandible. We also compare these results with the 2D and 3D macroevolutionary patterns of variation in cranial shape and the intra-specific mandible variation. The variation patterns were similar for 2D and 3D coordinate for all these comparative datasets. The differing results obtained at different evolutionary scales, give strength to the statement about careful selection of data not only in studies of morphological variation in caviomorphs but also for other groups of organisms.Facultad de Ciencias Naturales y Muse

Family diversity: a teaching experience in social work degree

El estudio del cambio familiar, la diversidad familiar y sus implicaciones desde el ámbito asistencial y de los Servicios Sociales es una parte fundamental de la formación del Trabajador Social. Este trabajo propone una experiencia vinculada a la innovación docente que apuesta por el enfoque interdisciplinar y transversal en la formación del trabajador social y tiene por objetivos: (1) describir una actividad formativa investigadora sobre diversidad familiar desarrollada en el Grado de Trabajo Social; y (2) presentar los resultados de investigación de la actividad formativa realizada. Un total de 216 estudiantes participaron recopilando información de 258 personas con edades comprendidas entre los 22 y los 85 años con ayuda de un cuestionario que evalúa aspectos relacionados con el concepto de familia y la aceptación hacia los nuevos modelos familiares. Los resultados de esta actividad mostraron que las personas entrevistadas por el alumnado tomaron en cuenta para definir el concepto de familia criterios funcionales y relacionales. Además, se observó que el grado de aceptación hacia las diversas formas familiares era elevado, aunque se encontraron diferencias en función del perfil del entrevistado. Esta actividad favorece la toma de conciencia por parte del alumnado de la importancia de la investigación social en la práctica profesional así como la existencia de prejuicios ante determinadas situaciones familiares no convencionales.The study about family change, family diversity, and the implications for care and Social Services fields, are central topics in the academic training of Social Workers. The present paper shows an innovative educational experience characterized by an interdisciplinary and cross-curricular approach. The main purposes of this paper are: (1) to describe an educational and research activity carried out in the Social Work Degree; and (2) to present the research results obtained in the activity. A group of 216 university students collected data about a sample of 258 subjects (age range: 22 to 85 years) using a questionnaire focused on the concept of family and the acceptance of new models of families. Results obtained showed that the concept of family was mainly based on both functional and relational criteria, and also a high level of acceptance of the different types of families, but with differences associated to the subjects’ profile. For students, this activity promotes the awareness of both the importance of social research for the practice and the existence of prejudice about nonconventional families.El presente trabajo ha sido realizado en parte gracias al programa de becas de Formación de Personal Docente e Investigador (FPDI) de la Consejería de Economía, Innovación y Ciencia de la Junta de Andalucía

Selection of CSI-based precoding techniques in the HF channel

Multi-carrier modulations are widely employed in ionospheric communications to mitigate the adverse effects of the HF channel. In this paper we show how performance achieved by these modulations can be further increased by means of CSIbased precoding techniques in the context of our research on interactive digital voice communications. Depending on communication constraints and channel parameters, we will show which of the studied modulations and precoding techniques to select so that to maximise performance